Hi! My Dorico performance was painfully slow. Slow at startup, loading projects, slow interface. So I tried different things.
When I deleted (x86) paths (Edit/Preferences/VST plugins/) the problem was solved tough I really dont understand why,but it can be worth trying 
/Mikael
Behind the x86 path are all 32 bit programs and plug-ins. But Dorico is only 64 bit.
Dorico scans for plug-ins on start-up and it is a waste of time to scan the 32 bit plug-ins.
Well just discovered that the paths reapeared after restart though they didnt affect the performance this time. 