"Our repository settings doesn't allow us to merge otherwise" <-- then go fix those settings!
#debian experimental now has u-boot-asahi. This together with already available m1n1 and asahi-fwextract you can now run update-m1n1 command and have all the bootloader parts from official debian repos. (Missing kernel and dtbs.)
BEWARE: This is a pure mainline u-boot, missing Asahi tree functionality like: M2 keyboard, multi-(Linux/BSD) booting and some USB parts.
A quick note that the new year started with asahi-audio being accepted inte the #Debian archive and swiftly updated to latest version. This means testing/unstable now has a complete userspace #Asahi audio stack! Still lacking an Asahi kernel in the official archive though, so check out https://wiki.debian.org/Teams/Bananas for usable third parties (while we wait for mainlining of kernel parts)!
Another precondition for the #asahi audio stack in #debian on it’s way to unstable with lsp-plugins 1.2.14-1 upload.