@afta8 thank you! Though I am looking for a replacement vst for usage in Bitwig conversions, so I am using the LUA Protoplug VST and already created a very similar plugin now, maybe even more useful due using a variable allpass filter.
The stereo enhancer is useful for me esp. on material which originally wasn’t mono compatible, so the logic is like: not mono compatible + not mono compatible = mono compatible
Still that surround algorithm… I really think now it leaks in the middle signal into the side and vice versa, done by purpose, in a modulated way. That’s why I once thought it was buggy and reported it as a bug, assuming it should have been a simple stereo rotation, but in fact, it isn’t that simple.