Thanks, gave it another try.
It's working perfectly fine, but will require a routine to maintain... the nature of a workaround
I still can't help but wonder, is it not possible to simply change the default rating tag from 'rate' to 'Rating'?
Hmm, I don't know. I mean, once you set everything up for use in MB and MB writes to 'rate', why do you need to maintain anything further? You just have to copy 'rate' to 'Rating' (for files whose 'rate' is filled but 'Rating' is empty) if you decide to migrate to fb2k at some later date. That is unless you are thinking about jumping between fb2k (or some other program) and MB regularly.
2: AT YOUR OWN RISK! make a copy of your Configuration.xml file before you attempt this!
open the Configuration.xml file from your MusicBee installation folder with a text editor
in the <CustomTags> section insert in the alphabetical sequence
save into MB and start.
<Tag id="Rating" id3v23="POPM" id3v24="POPM" wma="WM/SharedUserRating" vorbisComments="RATING" mpeg="Rating" ape2="Rating" />
Not 100% sure if this one will work.
you may have to re-scan your library to get MB to recognise the changes.
Ah, thanks bee-liever for chiming in.