As my post history shows I have struggled with this feature for years myself and stopped using any of the comments, ratings & description fields in DOpus altogether for the exact same reasons you mentioned. Changing files is the absolute no-go for me, too.
I started developing custom scripts to store data in ADS the way I want but that wouldn't be necessary if DOpus were always using exclusively ADS. On the other hand, I fully understand the reasons and the benefits of current behavior for non-power users. DOpus devs serve a broader user base than you or me but it breaks my workflow and quasi-OCD nonetheless. When I put a comment in multiple formats at once, DOpus saves some values in the files (and those in completely different standards like ID3, EXIF, and whatnot) and some in ADS. And depending on the format one of 2 fields, comments and description, conceals the other despite each having a different value and both columns show the same value. What DOpus does works mostly for most, but not for me.
I was thinking about requesting one or two features for quite some time so that we can exclusively use ADS, like enumerating existing streams and user-definable fields in a user-definable ADS name in metapane (inspired by MP3Tag's custom sidepanel-fields feature).