Scuse if this is a post rehash, the only ones I’ve found dont quite answer the Q, but is there any way to tell if what plugin version (e.g. VST2/VST3) is already loaded in Cubase? Reaper for e.g. details this stuff, makes it really easy to migrate/update from older VSTs. I thought there may be a repeat of the /// thing but I can’t (yet) find any way to show that on already loaded plugs.
Thanks in advance… 
You can see plugin manager, under studio menú
If you click the dropdown arrow on the plugin insert, it will show you these 3 vertical lines next to the plugin if it’s VST3:
So when you’re searching for the plugin to load, look for that indicator next to your search results so that you are adding the VST3 version whenever you want to be using VST3.
If the plugin is already loaded and, as you were asking, you want to know what plugin is already loaded in the project, that’s when you click the dropdown arrow. Or, as Italyuser said, if you want to see the broad overview, open the plugin manager and look on the far right side, under “Instance.” Then click it to sort it by instances (to avoid having to scroll down to see all the used plugins).
Awesome yeahimsteve, thank you, that first part re: drop-down triangle was more what I was looking for. I noticed the in-plug triangle drop-down gives a version history rather than if VST3 or not (I’m on Pro 12, appreciate it might be to do with that).
It’s to do with older projects and wanting to migrate older plugs to VST3 as I’m having issues with CPU load, my orig thread didn’t made that clear.
Edits because it would help if I explained myself better. 
Ta too Italyuser. 