[HTC One Mini 2] xxxmadraxxx:
Just a wee update from me on this [ref. my earlier posts in this thread, complaining about the unusably slow camera on the missus's Mini2, after installing this ROM.]:

After thinking that I had [at least partially] solved the problem by 'downgrading' to an earlier version on HTC Camera, we found the same as [MENTION=751547]ExB[/MENTION]; after a few days usage, the camera interface would start lagging again and we'd be back to the 30sec gap between launching the app and camera GUI becoming responsive. Then another twenty seconds or so between shots, while the photo was saved to disc [and this was at the lowest resolution setting].

As you can imagine, the missus has been bending my ear to just put the original software back on the phone as she says it worked fine, before I started tinkering [ahem!]. But I'm trying to avoid that if I possibly can, as it'll be a major hassle restoring the phone to some ancient version of Sense [Kit-Kat?], probably losing root in the process and, no doubt, several of the apps will no longer work. So, I'm trying to think of every possible reason for seeing this godawful performance and eliminate them all, before rolling back to stock.

I don't hold with the view that this abysmal performance is entirely owing to the fact that these phones are just too lacking in RAM to be expected to run current versions of Android. Yes, we might expect some slow-down and maybe a bit more shuffling apps in and out of memory because of the limited RAM, but not delays of half a minute between clicking on a button and <something> happening!

The hardware is getting on a bit, but it's not completely obsolete.

Anyway, the other day I suddenly had the thought that perhaps some of the slow-down might be owing to the speed with which LineageOS was able to read/write from the SDCard.

[I have used the "adopt as internal storage" since the advent of Marshmallow].

So, I popped the SDCard out for a look and found that, although Class 10, it was rated U1. I popped the SDCard on my HTC One M8 and found that while that was also a Class 10, it was rated U3...

https://en.wikipedia.org/wiki/Secure_Digital#Speed_class_rating

...so even though, in theory a U1 card should be fast enough unless you're trying to shoot 4K video, I did wonder whether the [relatively speaking] slower SDCard in the Mini2 might be contributing to lag.

I re-inserted the SDCard and migrated the data from the SDCard back to internal storage [luckily there was just about enough room to do so, without having to delete anything], removed the SDCard and rebooted the phone.

Result: The HTC camera app launches in about 3 seconds now and the GUI becomes responsive in somewhere around 5 seconds. After taking a photo, it is written almost instantly. Clicking on the photo thumbnail launches the gallery app in somewhere between 5 and 10 seconds and, swiping through gallery images seems as smooth as on my HTC One M8.

Now, the humongous caveat here is that I only tried this "cure" yesterday and, as some of us have found out, this sluggishness can seem to have gone away, only to return after a few days usage. So I'm not going to start celebrating yet. However, it may be another thing to consider, if you're experiencing a lot of slow-downs and are using your SDCard as "adopted storage".

In the mean-time, that nice Mr. Amazon should be delivering a new U3 SDCard today for the Mini 2 and I'll try that and see if the phone is more responsive with a faster SDCard. If not, we'll just have to make do with internal memory [got about 2-3GB left, so a wee bit of wiggle room there]. And, with or without new SDCard, if the dreaded slow-down re-appears again after a few days usage, I think it's time to finally throw in the towel and roll back to the original Sense ROM.

Here's hoping!