@Gabriel

One thing you might try is to see if these same issue occur in the preview release of V21. That version will no longer rely on Visual Studio 2015 and all of its heft and has instead been built from the ground up. This is expected to be GA very soon and a preview release is currently available. You can install this next to 19.1, so it won't conflict with it.

https://collaborate.pega.com/discussion/robot-studio-v21-preview-2-now-available

The TLDR of your issues below is that it seems like your performance is certainly atypical. If you are opening solutions from a network location, try moving them to a local folder. That would certainly help. If your machine is minimally spec'd, you might look for an increase in RAM or processing power. If you have any security software that might need to whitelist Studio, that may also play a role.

For instance, opening solutions can take several minutes. I notice that it always tries to reopen the solution with the previously visited automations already open, which may be a source of the lag. When I delete the .vs folder within a solution, it opens in Studio quite quickly, without loading/opening any automations. Is there a setting I can edit to achieve the same effect, without manually deleting the folder each time?

I am not aware of a setting, but you can certainly close all opened documents before closing Studio. Right-click on any opened document and select "Close all documents". If you have a machine with lower specs, this can really help speed up opening as you've noticed. The .vs folder is part of Visual Studio and is where things like breakpoints and your open documents get stored. I have never specifically had to delete it, but I have done so before when creating a backup without any issues.

One other thing you can do is make sure your solutions are stored on a local drive. If you open your solutions from a network share, that can really hinder performance.

When closing tabbed automations that have been opened, there's a very significant delay (especially if I ask Studio to close more than one (i.e. right-click Close all Documents). This can lead to 5-10 minutes where Studio stops responding while it tries to close 5 or so tabs. What causes this delay, and is there any way to reduce it?

I suspect this is because your solution is opened from a network share or your machine has some sort of limited performance. This might also be due to security software scanning everything being done by Visual Studio. I would say this is atypical performance though and should be examined by your hardware and security teams to see if there is anything that might be hindering your performance there.

I've noticed delay even when adding automation links between components, where Studio will seem to not respond for several seconds, and then suddenly incorporate the new link. This feels like it should be a relatively process-light task, are there any suggesting to what could cause this delay?

I suspect it is a machine-level performance issue as stated above. Either that, or you are opening your solution from a network share rather than a local copy.

Finally, I notice it saves the zoom level/position for each automation file. Is it possible to disable this?

Not that I am aware of. There is a Toolbar button that will fit all your automation elements in view for you. It is labelled "Fit to screen" if you however your mouse over it. It looks like a magnifying glass surrounded on all four sides by lines.