I’m German. Foreign accents (I.e. some foreigner speaking German) are either funny or cute to me. If I feel neither, that’s probably because I need to concentrate to understand. In German accents, a Bavarian accent, a Saxon or a Frisian one turn me off.
In (to me) foreign languages, I don’t care, meaning that I’m just as fine with „Oi com frum Birmingham“ as with a posh Oxford accent. Also the southern French accent is fine with me, as well as the northwestern one. I’m also fine with Breton, but that’s a language, not an accent. And I don’t understand the latter very well anyway, let alone speak fluently.
You’re looking for a block level incremental backup solution. This can either be achieved using filesystem based snapshots (ZFS, BRRFS) or using dedicated programs. I know rdiff-backup , restic and duplicity use block-level diffs, not sure about rsnapshot.