@nina_kali_nina @0x47dfIf you're willing to settle for building embedded images instead of full distributions, buildroot works really well for older hardware. I'm running 6.16.7 on a 486 w/64MB of RAM (as a BGP/Babel router using bird 2). buildroot also actually includes cip kernels as an option if you wanted to stick with that.
I haven't used Yocto at all (way too much for what I actually need), but my understanding is it's more along the lines of a build-your-own-distro if you want to put the effort to handle many older machines.