> Quickly banned by IP and deleted.

Yes, please add yourself. See this is working out already. :)
@davisjacobym, god mode activated. Proceed with caution. You can literally delete the everything.

Please read the post about mass deletion in the original post. It's a few clicks, but it can purge and IP block the 7-10 spammers we get every other day.
Although the instruments may look the same on the surface, what's happening under the covers is quite different. Carla has support for instruments that LMMS does not natively. Furthermore, on Linux LMMS only supports VSTs through a Wine layer, which affects the stability and performance of a plugin....
First time I've seen this proposed. Please file a bug. https://github.com/LMMS/lmms/issues
Being worked on here: https://github.com/LMMS/lmms/pull/3521

The GitHub bug tracker linked above is the proper place for bug reports. :)
This happens to me all the time and I have to pitch the instrument a few semitones to get the right sound.
No well known composers use it, but "professional" is subjective. I've used LMMS for paid project (some children's books) which would be by definition "professional". The best tracks we're aware of are on our Best Of albums as well as a few tracks that never made it (most on soundcloud). Macrowave h...
It's a fairly common complaint that hasn't been addressed yet.

For composing, I use Mac, Windows and Linux in that order. Too late for poll. :)