is still an issue in 0.4.14rcl
The VST GUI is lost if the instrument preset is closed
This behavior can be demonstrated with the popular Karma-filter, but aplies for next to all VST based effects i have tried, (or the VST behaves like described in https://sourceforge.net/tracker/?func=detail&aid=3595560&group_id=105168&atid=640434\)
Could the solution that was used for the mixer-sizing be an option?
The problem makes it imposible to use most VST based effects.