Maybe this article is as dated as my knowledge but support of 2.4 is (or was?) rather poor.
So I wonder if you gain anything by migrating to 2.4
https://picard-docs.musicbrainz.org/v2.4/en/config/options_tags_compatibility_id3.html
Appreciate the help, and yes, I've been working with the Picard Dev's in order to figure out workarounds to help me have consistency between programs, because I DO use Picard to create my initial metadata for my files.
But to answer you I have to explain "why" I'm needing to go to 2.4, but be aware my saying so sadly will cause certain "advocates" here to personally attack me rather than understanding the problem and trying to help.
So, the simple answer is MusicBee is forcing the NULL aka double back-slash separator when Saving in the Tag editor for those tags with multi-values, and Bee is doing this with 2.3 files also even though the NULL separator is NOT actually supported for 2.3.
So, I'm trying to switch over to 2.4, and it's causing all kinds of problems in my ability to edit files across applications (Mp3tag and Picard, the actual professionals when it comes to tag editing). I've had to switch from using the Semi-colon and space, which is the most common standard to the back-slashes, and NONE of the tag editors do what MusicBee does in forcing null, they save/use what WE want to use as a separator, so that's causing issues trying to figure out "work-arounds" for various things.
Believe me, I wanted to use 2.3 for compatibility reasons, and I had set up everything perfectly. I use Picard to get my primary data, then I edit as needed in Mp3tag, and then I use MusicBee as my player and use the editor as needed to add missing things.
However, when another individual on the forum brought up the subject of their separators being changed on him when saving in the Editor in MusicBee, I then discovered MusicBee was doing this with my separators as well (had noticed it happening but hadn't had a chance to look into it yet), and everything is now messed up. I was wanting to use 2.3 so I (nor my sons) wouldn't have any issues playing the music files on whatever device, but doing so prevents me (and others I've talked to) from being able to use the MusicBee editor, and while I would do that, there are some things such as Lyrics and other things in which using the MusicBee editor is useful. All because MusicBee choses to be "outside the norm" in relation to Tag editing.
I'm not the only one with this problem, others are highly disappointed about it just as I am and have contacted me in PM, on other forums etc telling me the same frustrations. When the other guy and me then tried to explain that this was an issue, we were given an education about Null separators, which was understood, but when we further explained that this is a problem and how, we were continually abused, treated as if we didn't understand, so several attacked the two of us who tried to raise these issues, and the other one they attacked has been using tag editors for 20 years, so he wasn't a newbie, and me after the initial explanation was well aware and understood what the NULL separator was, but they continued to personally attack him and me as if we were "disabled" and thus deserving of being personally attacked, when we tried to explain that this "forced" standard needs to be changed, especially since it's one nobody else forces on people, that it causes several problems, but us trying to explain the problems just further enraged the abusers who continued doing so across more than one thread.
Anyway, now you know, and here comes the personal attacks, justifications for it, etc. Rather than recognizing the problem, and encouraging the current process to be changed, especially since NULL separators are NOT the standard for 2.3, yet they would continually say it WAS the standard, and then berate us when we explained it wasn't. But, they do this instead of helping me and others so we don't have the problems anymore. BTW, the other editors don't even force it on 2.4.
I didn't want to mention this because it would derail the thread and get it closed like they've done with others, but, you asked, so this is why....
Let's hope they can hold their personal attacks and just focus on the issues mentioned... But, I won't hold my breath.