I don’t know about hardware support, but I found this article on box86.org which seems to be the best alternative to rosetta on Linux. The performance drop on box64 vs native is still much greater than the performance drop in rosetta:

https://box86.org/2022/03/box86-box64-vs-qemu-vs-fex-vs-rosetta2/

Edit: many infos about Rosetta under the hood: https://github.com/FFRI/ProjectChampollion

I found nothing, that implies that there would be specific hardware features in m1 for making the translation faster. Only that it does translation mainly ahead-of-time (AOT) and saves "that version" of the app somewhere as cache). I only scrolled through it and did not read it all, so maybe I missed it.