ok so I finally had a reply form HR about my request. My official request was this:
REQUEST:
"Dear Lotte,
 
Following our last meeting, and as asked by you, I’m sending this formal request with the details of my intended planned leave period and details of it.
 
My request is about taking a period of time away from work, ideally starting around the end-of-year break when the lab closes in December 2025 (approx. 20-24 DEC 2025), and returning around the beginning of June 2026 (e.g.: 1 JUNE 2026). The idea is to take my remaining holidays first, followed by unpaid leave, for a total of approximately five months. This will allow completing the year effectively by the end of DEC this year.
 
My request arises from several open conversations over the past months with different people in the company including my Direct Manager, yourself at HR, our Operational Manager, our General Manager, and our Senior Global Director for Diversity, Equity & Inclusion. I’ve taken the time to consult broadly my current situation at work also through the help the company gives and outside the company with therapist.
 
After almost nine years here at the lab, with full time work and contributions, and near 13 years away from home, I have reached a moment where I need to pause and reset. This is a temporary break with the clear purpose to regain perspective and return with renewed spirit. The goal is to have a better structure at work that allows professional growth, and outside for personal development as well.
 
I trust that the responsibilities I currently handle independently can be safely maintained during my absence, as has been discussed with my Direct Manager. I remain committed to my role and to continuing my work after this pause.
 
At my return I intend to bring a better direction with focus also on new areas in my work. I plan to explore opportunities for developing failure analysis, especially looking into new technologies that could expand our services. This includes among other possibilities: Battery Systems, Consumer Products, Additive Manufacturing, AI, and further use of 3D Profilometry & other related techniques with intention to have more impact on Metrology testing. These initiatives, for example the area of battery systems, had a good reception by the Business Unit, and I believe align with the company’s goals ahead.
 
More importantly, this will give me much better perspective and allow growth in here. I hope to return to a framework that allows real professional growth within the company and outside personally, something I currently feel is missing.
 
I’d also appreciate if you could inform me on how this would affect things like next year’s holiday allowance, other adjustments needed to the current year’s holiday balance, and if there are other HR-related implications I should be aware of while taking unpaid leave. I’m happy to help with any paperwork/etc. if required.
Thank you very much in advance for considering this, I’m happy to discuss in person.

Greetings,"

And their reply was this:
REPLY:
"Hi Daniel
 
Thank you for your formal request for Leave of Absence.

For next year your leave rights will be (this will change offcourse whether you want to take unpaid leave):
 
ADV 2026: 104 hours
Vacation 2025: 160 hours ( to take before 1 July 2026)
Vacation 2026: 160 hours
BW: 127 +56 hours = 183 hours

Total: 607 hours
 
If you want to take unpaid leave this will affect:
Holiday pay and allowance – you don’t build this up.
Pension – no participation in pension fund. Changes in hours worked | PME pensioenfonds
No participation in voluntary assurances as the WIA assurance
 
Please consider the above.
 
If you know what period you want to take unpaid, I can calculate the exact leave rights.
 
Regards,"

--------

QUESTIONS TO YOU:
-What does their reply say in simpler terms?
-I'm owrking in the netherlands, she mentions some potential issues, can you explain me in good detail but in simple terms what exact problmes i will have?

--------
STRATEGY *MOST IMPORTANT*
-If i take all my holiday rights as he mentions that means i would be using all my holidays at once, but i will be back to work straight on for many months and i dont see this beneficial either. 
-My idea is to take all my holidays from 2025 to be used by july 2026. and i think after that i should use unpaid leave. if im understanding correctly she has to recaulculate the holifay rights for 2026.
-my idea is to first of all: get enough time away, so my goal is to be away from around 20 Dec until idealy 15 may, or 1 june 2026.
-using my rights from 2025, i have some hours there. but she did not tell the total amount of hours i have, so she made a mistake. my current balance for 2025 is this:
ADV 2025	24 - To use before 31 Dec 2025
TvT Verlof	21 - To use before 31 Dec 2025 ideally
Vak Wettelijk 2025	160 - To use before July 2026
Vakantie Boven Wettelijk	127
-So all this means, if im correct, that taking unpaid leave in 2026 will incurr in decrease of my holiday rights for 2026 correct? I work full time 40 hrs per week, so when i work less i have less holidays i presume.
-We must also consider national holidays from 20 Dec 2025 until 1 June 2026 on my favour, because this are basically additional holidays. The ones that should count on my favour are the ones that land on weekdays. But here is the complete list:
25, 26 DEC 2025
1 JAN 2026
5,6 APR 2026
27 APR 2026
14 MAY 2026
24 25 MAY 2026

-So THE OBJECTIVE IS TO GET AS MUCH PAID HOLIDAYS NEXT YEAR, AFTER THE BREAK IM INTENDING FROM 20 OR 23 DEC UNTIL 15 MAY OR 1 JUNE. THIS WHITH THE MOST OPTIMAL COMBINATION OF HOLIDAY RIGHTS AND UNPAID LEAVE.
*CONTRAINS: 
1.-BECAUSE I ONLY HAD ACQUIRED FULL HOLIDAY RIGHTS IN 2025, THESE ARE THE ONLY ONES THAT CAN BE FULLY USED. 
2.-IF I UNDERSTAND CORRECTLY, IF I DECIDE TO TAKE UNPAID LEAVE TO COMPLETE MY ENTIRE TIME AWAY AFTER MY HOLIDAY RAIGHTS OF 2025, MY BALANCE OF HOILIDAYS RIGHTS FOR 2026 WOULD BE AFFECTED.
-THEREFORE I NEED TO FIND THE VERY MOST OPTIMAL WAY TO GET THE BEST BALANCE OF UNPAID LEAVE TO GET AS MANY HOLIDAYS RIGHTS FOR 2026. SO THE IDEA IS TO HAVE THE MOST BENEFICIAL BALANCE OF UNPAID LEAVE AND HOLIDAY RIGHTS IN 2026.
-SO I BELIEVE HR WOULD NOT TELL ME HOW THEY WOULD CALCULATE MY HOLIDAY RIGHTS FOR 2026 BY TAKING UNPAID LEAVE. SO WE HAVE TO COME UP WITH A PROPOSAL THAT WILL ALLOW ME TO SEE HOW MUCH THEY DEDUCT OF HOLIDAY RIGHTS OF 2026 PER UNPAID LEAVE DAY. SO THE QUESTION IS: HOW MANY HOLIDAYS ARE TAKEN AWAY FROM 2026 BY DAY OF UNPAID LEAVE?
-SO I MUST COME BACK WITH A PROPOSAL TO THEM THAT SHOULD LOOK LIKE THIS:
I want to take all my holiday rights from 2025 including: ADV, Vak Wettelijk & Vakantie Boven Wettelijk.
After my holiday rights, I want to take of Unpaid Leave "X amount" days. In order to be outside work until at least 15 May or 1 June.

-Then the "X amount" of days must be defined here by you, so when they come back to me with they calculation, we can figure out how many holidays are taken away per unpaid leave day taken.

CAN YOU HELP ME WITH ALL OF THIS PLEASE!?!??!