You could consider converting your music library to OGG files. Instead of ID3, those use Vorbis Comments, which do allow multiple artist tags, and are significantly more flexible in general (for better or worse). There’s other advantages, too, like them using less storage space.
However, do mind that even the most flexible standard can’t do more than the music players you use. If those can’t display and filter for multiple artists, you’ll be out of luck.
And OGG is newer / not quite as popular, so it is quite possible that music players don’t support it in full extent.