Bug with rescan and ROONALBUMTAG?

Core Machine

nucleus, rock, irrelevant to problem

Network Details

switched 100/1000 ethernet, irrelevant

Audio Devices

USB connected Benchmark DAC-3, irrelevant.

Library Size

220,000 tracks

Description of Issue

I’m using ROONALBUMTAG to enable me to import my album ratings, created over years prior to roon, into roon. Works fine. I have tag values like “unrated”, “rating = 8” etc. I’ve imported thousands of these tags into my roon library. When I listen to a previously unrated album and rate it, I use mp3tag (outside roon) to change the tag from (say) “unrated” to “rating = 8”. It should get picked up on the next rescan or forced rescan. Well, it doesn’t. However, if I select an album that I have changed the tag on, and in the album view select edit/rescan, the new tag pops up.
why do these 2 ways of initiating a scan differ, and why does the bulk rescan fail to modify the new tag values while the individual album view scan does make the change?
this is repeatable, and I have tried it on multiple albums. I recently modified the ROONALBUMTAG on about 50 albums after rating them, and none of the modified tags showed up in roon on a forced bulk rescan, yet those I tested did import the changed tag if I used the individual album view.

added note: roon is pretty opaque on implementation. I’ve noticed that forced rescans are quite fast, and speculate that, similar to full and incremental dumps, roon may be doing a lightweight scan and a deeper scan. Perhaps a deeper scan will occur automatically and pick up the tag changes? At any rate, users have no insight or control of scan depth, if there is such a thing, and my tag changes were not picked up automatically from roon file watching, at least in the first 24 hours.

ok, I think this is a serious issue that deserves attention. Under some circumstances, if you edit metadata tags in your library, then rescan with roon, the changes are not picked up. forced rescans, scheduled rescans, rescan after boot can all miss some changes. In my case, I found that the individual album rescan (see original post above) did pick up the changes I had made, but my assurance level that the roon view is up to date with my actual library content is diminished. Also, I had to scan 40+ albums (whose metadata I had edited) individually in order to incorporate the changes. Note I tried several times to do a forced rescan, tried restarting the server, waited for 48 hours for roon to somehow notice the changes before giving up and using the individual album rescan feature. I made no changes to the filesystem or album metadata between trying the bulk scans and fixing things with the individual album scan.
If roon chooses some fast technique to facilitate rescan, fine, but once in a while a full, indepth rescan is needed of both the file and the metadata. Right now it appears users are helpless to manage this - well, short of a catastropic full database regeneration.