I’ve been running sid (unstable) on my htpc for almost a year now without any problems (wanted Debian, because that’s what I know, but also wanted HDR support, which came with plasma 6, wichich was only in sid). Just as stable as Bookworm so far (anecdotally).

I’ve actually been thinking of moving my main desktop from mint Debian edition over to sid as well.

Sid is even one step more unstable then testing, so testing should be no problem either