I haven’t had that level of issues with CIFS on Apple platforms in general.

For most of iOS 18 there was a bug where iOS and iPadOS simply couldn’t connect to Samba shares on Linux but that has since been resolved.

Apple does implement some custom functions that make CIFS (Samba or Windows based) shares less performant than Apple platform served shares in certain situations. Especially for server side copy. TrueNAS has recently patched this so that it works.

Adopting/inheriting a CIFS-backed Time Machine share is needlessly precarious.