Apple Silicon Macs will not run unsigned binaries, but the binaries can have any signature, so you can just generate one yourself and add it. There's no need for a developer account, or any other external party. And there are no issues with legacy support either, because ARM Mac binaries didn't exist until now (and the requirement does not apply to Intel apps being run via Rosetta).
This really isn't a big deal.
I was initially worried that mandatory code signing would prevent me from hex editing binaries (which is a thing I do sometimes), but I recently learned that codesign can replace a binary's existing signature. So even that shouldn't be a problem.