[Desire HD Android Development] Mustaavalkosta:
aceopt

"aceopt" builds seem to be working decently for the things I wanted to test them before releasing them with installation instructions so here we go.

Disclaimer: You will lose everything on your sdcard if you follow these instructions so take appropriate steps to secure your data before continuing. Also this will be a "clean flash" from the start due to different partition layout.

Prerequisites:

TWRP 2.8.7.0 for aceopt by [MENTION=2836769]jrior001[/MENTION]

aceopt build of your choosing

Gapps and addons if you want them. IIRC, there was around 400-500MB space left on new /system partition after flashing base gapps package so there's a bit more room for addons.

If you have already partitioned your sdcard you may want to repartition it to have only single partition because you won't benefit from having separate sd-ext partition with this variant build. I won't write anything about this as I expect you can reverse what you have done yourself.

Installation instructions:

Flash TWRP-aceopt-2.8.7.0-unofficial.img in fastboot or your current TWRP (Install > Images > etc.)

Reboot to recovery even if you are already in TWRP. You need to reboot to be in newly flashed aceopt TWRP.

Wipe cache and system under Advanced wipe.

Convert your sdcard to either EXT4 or F2FS under Advanced wipe by choosing data partition > Repair or Change File System > Change File System > EXT4 or F2FS.

(Optional) If you had your old /data partition formatted as F2FS you also need to convert it to EXT4 meaning converting system partition in the aceopt recovery.

At this point your sdcard is completely empty so you will need to move the ROM zip and any additional zips into sdcard or use adb sideload.

Install cm-12.1-XXXXXXXX-UNOFFICIAL-aceopt.zip and gapps.

Reboot

Notes:

This is no miracle cure to old device. It will mainly provide more storage space for user apps. Nevertheless, with fast sdcard this is likely as fast as this device will get due to pre-optimization involved and also due to usage of default ART dex2aot filter which is set to interpret-only in regular ace builds to save space which means most of the speed improvements that ART brought are gone.

Apart from pre-optimization, dex2aot filters and different partition layout these builds are exactly the same as regular builds.

Update flashes work as usual. If you want to perform clean flash afterwards just do factory reset and manually format system. DO NOT manually format data under any circumstances unless you want to lose everything on emulated sdcard too. You can think of formatting data in aceopt recovery is the same as formatting your sdcard in regular ace recovery. I have accidentally completely emptied my Nexus 5 by doing this so many times it's not even funny anymore.

If you want to switch back to regular ace builds later on you will need to format your sdcard again to have meaningful directory structure in it, or manually fix it.

Make sure you regularly backup your sdcard as a whole to protect yourself against sdcard hardware failure which will technically make all your user app data and sdcard data to disappear. I use Win32DiskImager to backup my Raspberry Pi sdcard and it should be ok for this purpose too on Windows. You can find other ways on other OSs from your favorite search engine.

Old /data is now /system

Old /sdcard is now both /data and /data/media (emulated sdcard).

Old /cache is still /cache

I might have forgotten something from this guide post. I'll update it if necessary.