[Nexus 7 (2013) Android Development] ipdev:
Sorry for the extreme delay. :o

- A little OT but, since it's device related -

First.. You do not need to run both partitioning scripts. ;)

One or the other would be enough.

UA is Unlegacy Android.

Unlegacy Android ua-wiki - Link

Very skilled and knowledgeable team who are often involved in or share with other groups. LineageOS for example.

Some of the updates, patches and fixes for Nexus7 (besides other devices) come from one or more of them.

The difference between the UA-TWRP and regular Official TWRP, basically UA has support for a separate VENDOR partition.

These devices did not come with a separate vendor partition like newer devices.

Older devices, like this one, vendor is part of the system image. On newer devices, vendor is separate and symlinked into system.

Clamor's partitioning script changes quite a few and adds an extra partition space for vendor.

A big change in the partition table !

Make sure you read his note about flashing stock factory images.

This will bring the older devices like Nexus 4, 5 and 7 more inline with newer devices.

Then a common/custom vendor image could be created and used instead of incorporating it into each ROM.

Someone(s) would have to maintain and update these common/custom vendor image for each device.

So, UA-TWRP or regular TWRP doesn't matter until a separate vendor partition is utilized.

Version 3.3.1-0 and 3.3.1-UA would be TWRP 3.3.1 so both are build from the same base.

1. Not sure if any use the separate vendor partition yet.

UA will probably be the first if I had to guess.

2. If it's already (re)partitioned with Clamor's script, I'd leave it alone.

The only thing you would do is reclaim some space for userdata.

As long as the partition is equal to or larger than the image you are flashing to it, you will have no problems.

You can flash and use the official TWRP on a device that was partitioned using Clamor's script since the recovery partition is larger than the image (official TWRP) being installed. It will ignore the vendor partition but, since it's not being used it's no big deal. You could also use the UA TWRP if you wanted to.

The system partition is 1.5G so, you shouldn't have an issue installing any of the current custom roms.

Note to all.

As for (re)partitioning you only need to do it once.

Well as needed would be more correct.

I've really been meaning to find a good explanation on this to link people to..

So I'll try to explain it quickly.

Partitioning is different from resizing an image.

When you flash an image in recovery it basically restores a backup to a specific partition. As long as the image is equal to or smaller than the partition, it will restore the image. If the image is smaller than the partition it is being restored to, there is unused/extra space in the partition. To make the extra space available, you have to resize (expand) the image to use the whole partition space.

When you wipe/format a device you are just erasing what is stored in the partition.

The only time a partition size changes is if you manually change them.

Once the partition for system is (re)partitioned to say 1.2G, it will always have 1.2G allocated for system even if the system image you flash is only 850M. System will only have 850M available since the rest of the (system partition) is unallocated. So you have to resize system to fill the whole (system partition) to be able to use the 1.2G space allocated.

To keep it simple, I will not try and describe the new dynamic partitioning (super partition), not related to older devices.

Implementing Dynamic Partitions source.android - Link

Sorry for the long post.

Hope I helped more than confused.

Cheers all. :cowboy: