There are some brilliant LEGO creators with many designs on YouTube out there who choose to remain anonymous- who put some of their designs on MOCHUB but not others. (In particular ones relating to pneumatic engines.)
There might be a reason for this I’m missing.
I could comment on YouTube but then my comment would be against my name for all to see forever, and I’d prefer a communication method more discreet.
What is the appropriate way to request a creator to add more of their designs to MOCHUB?