Is that something you’re looking for? As a practical matter, the effort to maintain multiple release branches and backports – compared to the norm of just maintaining a single main branch – is an outsized effort, available to only well-founded FOSS projects, usually by having an industry sponsor that makes it a priority.

I posit that the grand majority of selfhosted FOSS software, by project count, does not have back ported branches. And so production environments will want to set up an offline validation setup to evaluate update, prior to making the switch. Not convenient, sure, but not exactly insurmountable either.