At least on PC, it seems like holding one of the mentioned modifier keys when clicking on an insert, opens the plugin gui much faster (instantly as opposed to having a slight delay). Anybody an idea what this is about? Why don’t they open as quickly with a regular click?
This has been a topic of discussion in the past. If I remember correctly, even a Steinberg rep was involved. Unfortunatly I can’t find that topic and I don’t remember the final reason that was discussed. Try searching some more. I hope you find the info.
Regards. 
What the??? Same on Mac, with the CMD key. So weird…doesn’t make any sense that it wouldn’t be that way all of the time!
AH! On Mac it’s directly related to how fast you have your double click speed set to. This shouldn’t be the case and can be eliminated, though I don’t know how complicated it is to do so.
I just tried setting mine to as fast as it will go, and the plugins open ALMOST as fast as when holding CMD. It especially sucks for those who want or need to have a longer double click time set up, but it’s not good for anyone.
Please fix this after all of these years, Steinberg – it shouldn’t be happening.
Thanks for the link, i must have overlooked it. It‘s very strange that this behaviour seems to be by design…