Please don't flame me because I can't use the crocus driver properly ((it has real issues on my system)). If I can accomplish what I'm trying to do, I am 100% willing to do this for all future releases and make it publicly available to the community as I'm sure there's a bunch of folks out there that could really benefit from this. Here's some relevant info:
- Mesa moved the i915 & i965 drivers into the MESA-AMBER branch
- Final MESA version ((before moving to AMBER branch)) that includes i915 & i965 is version 21.3.7
- My system is an Intel N3150 + 8GB RAM + SSD
- I'm severely disabled & live on disability ((so I can't buy new hardware, otherwise I probably would have already!))
- Everything was great on Matrix builds
- Unfortunately THIS chipset seems to work very poorly with the CROCUS driver ((both the Generic & Legacy builds)). It's very 'laggy' during simple 1080p output. I can't play 80% of my content anymore ((which worked great on Matrix))
- In addition to the bad performance, I've noticed that the RGB Full/Limited output doesn't behave anymore. Not sure if it's mesa related though.
- I've noticed similar issues on Linux builds - switching to the i965 driver fixes everything ((mesa-amber)).
- I've tried switching the driver in use inside LE to the other Intel ones but they don't work ((kodi GUI doesn't load - as expected))
- I'm comfortable with Linux, building programs from source, I have built LE x86 before successfully ((I LOVE YOUR STREAMLINED BUILD PROCESS!!!))
The situation kind of sucks because many i915/1965 devices were supported by mesa for what seems like decades. I saved up $$ for an entire year to buy this system about 2-3 years ago.... (facepalm). lol 
With most Linux systems I can simply add the mesa-amber package and remove the vanilla mesa package - simple.
I want to build x86 Generic/Legacy ((I'm willing to maintain both)) with either MESA-AMBER ((preferred)) or the final MESA v21.3.7. How feasible do you guys think this is?? It seems like it should totally be do-able from my perspective but I don't have much experience in actually "removing" & "pulling in/adding" or "replacing" software when building something from source.
At what point during the official LE build process would I start to make the relevant modifications??
Currently I'm brushing up & trying to learn all the Github commands and features to have a better grasp on everything. I've generally only used it to "clone" source code to my PC.
Anyways, I appreciate any assistance or guides/tutorials that one could link me to in which would be advantageous to my goal! I really hope to be able to continue using this hardware & provide it to others ((I'm sure there's tons of hardware this would benefit))
Thanks very much for your patience in reading the above!! 
I should also note that the performance issue I'm experiencing is for both Nexus & Omega builds - not just a specific build.
- Do any of the older Nexus builds use a mesa version before v 22???