I'd be in favor of that ONLY if macOS 12.7.6 is specifically considered unsupported. Let's spend a little more time figuring out what's missing.
Why not do both? Apply a fix that works on officially supported hardware (by macOS) now and continue looking for a fix that can be backported to older macOS 12 / Intel? They seem to be separate issues anyway.
There are reports that emacs-mac works fine with dictation on 12.7.6 so take a look at that code and see what they're doing differently?
Happy to take a look. Can you share details please?