Bootstrapping a fork from OpenBSD is not an easy task.
I decided to rename the ABI to be able to compile differently and make ABI choices on our own. The consequences of that is that every config.guess and config.sub file has to take into account openbsd* | iabsd*). Long story short, the whole base system is safe, now we're actively patching the ports infrastructure and individual ports too. Sometimes CONFIG_GUESS_SUBDIRS was incomplete (either it is on purpose but I'm sure it can be upstreamed already). The only supported compiler architecture triple is amd64-unknown-iabsd0.1. No cross compilation needed.
I put online https://ftp.iabsd.fr and https://firmware.iabsd.fr with a new public key for base, fw and ports. These are already included in the distribution on https://ftp.iabsd.fr/pub/IABSD/0.1/.