MrC and I had an interesting discussion on this over in chrisjj's thread about a similar issue.
For the record, I think this is worth fixing.
chrisjj's thread is a perfect example. The problem is, essentially, you can't "blank" existing fields that contain metadata at all via MCWS with an MPL, which makes it very difficult (if not impossible) to solve this problem via MCWS. But, as I noted, you
can solve this easily via COM.
So, if for no other reason than that I know if Matt was paying attention it would get right under his skin that the newfangled, cross-platform MCWS is "lesser than" the old crusty COM API, it is worth fixing.
But, also, as discussed in that thread, as long as it is limited to manually importing a single MPL file, I can't see the harm. The user has expressed explicit intent by importing a specific MPL, and you can't be blamed for doing what it says to do. You should trust explicit user instructions whenever not crazy.
To be clear, as discussed in the thread, I do not think you can do this:
* Automatically when importing anything (playlists or files) in a batch of any kind, because it would be far too easy to accidentally select a big group of files, some good and some borked, and hose your data.
* When it comes to in-file Tags themselves. We're only talking about MPLs here. The file tagging stuff, I think, does it correctly now, and doesn't trust suddenly blanked or removed tags.
But for MPLs, you can.
Or, at the very least, you could do something like:
If a field in an MPL contains a value that is not "null" (no characters) but only whitespace, then you blank it, and "optimize away" fields that contain only whitespace. That would be totally safe (no broken tool is going to write " " accidentally), and would accomplish the same task cleanly and without adding a weird special case.