can i delete the *1 fids and tell emplode/emptool to rescan the tags?

No. emplode/emptool don't look at the ID3 tags once the files are on the player. They deal entirely with the *1 files (actually, they read from /empeg/var/database and write to the *1 files).

Moreover, if you delete the *1 file, this is equivalent to deleting the *0 file -- emplode/emptool will treat that FID as unused, and will overwrite it the next time that you upload some new music.

If you were to port ID3 tagging to the player, it would be of very little use, unless you planned to retrieve the files from the player -- since once the files are on the player, nothing uses the ID3 tags.

I guess if you were using Hijack to stream from the player, it would be quite useful, though.

Anyway, if you're going to port ID3 tagging to the player, just make your app update the *1 files (and rebuild the databases) while it's there.