ok, after hours of naming variables and functions and confirming what you can find about algorithms in RomRaider's description of tables I decided to go for Launch Control for my vehicle just to see how it is done for WRX.
So I downloaded stock rom for the specific patch available for free, applied the patch and disassembled the result. Disassembled stock ROM too and the difference is just the LC code + constants. Now I can apply this to my ROM for which there is no LC patch freely available that I know of.
Pretty sure I will not use that to actually trash my gearbox
but other uses such as valet mode, custom ECU built in car security and water-temp based rev limiter seem to be easy to do. Plenty of ideas, just need to pick one and do it
for general disassembly it would be cool to have a program that could convert available XML files to IDC scripts to get automatic variable/constant/map comments