@pkouame I was looking at the Catalina Carbon's HIToolBox and noticed the half sized binary 4.7 MB (Catalina) vs 10 MB (the HS/Mojave one), then I remembered why, of course it's halved, it's fork'ed of 32 bit coding by apple, so I thought, since our HighSierra/Mojave kext/framework binaries are all still 32+64 bit (
@ASentientBot found also some 64bit Haswell), maybe this could cause some side effects on Catalina booting on unsupported Mac ?
I mean if Catalina kernel found a 32 bit coding into a binary to execute could this lead to a side effect or even unexpected kernelpanic ?
Then I remember another thing, if I don't get wrong, the HighSierra and Mojave "BaseSystem.dmg" should contain all kext/frameworks with 64 bit coding only, so in case it's not needed a disassembly to cut the 32 bit coding.
Don't know maybe this is unrelated, but I'd start to try using the kext/framework binaries only with 64 bit for our Catalina unsupported Mac.