You bet I can.
The beta version of my Plus install exists on a separate drive and so does the executable. I set that one up and ran that one to point to the database on my F: drive rather than my E: drive. The database folder is called TRS19_TEST (yes in caps) so I know which one is which. I wish we had bold and colors we could specify for folders, but it ain't that way for us.
I have done the same with other versions as well whether it's TRS2009, TS2010, TS12, and even T:ANE.
Now there is a catch with TRS2019 and Plus. If you are a gold member, you will end up putting Plus features into your TRS2019. Tony mentioned this in the forums back when TRS2019 SP1 beta was first out and I was going to setup a test for that one. The reason is both versions share the same code-base and the features are turned on and off by permissions. I have another software package that does the same thing. When I upgraded from Standard to Pro on Pianoteq, all I needed to do was put in a new software license key. They said that everything is there and all that was needed was to turn on the additional features. The upgrade, by the way, was $150 on sale! Pro is normally $850 retail.
I edit the shortcuts and put the build numbers and Drive on them, I update the build numbers on the shortcuts after patching. I have TANE and both versions of TRS19 on their own SSD drives so can easily find where things are.
I have tested that the Standard updates to Plus which it did both in the SP1 Beta which I didn't bother testing as it had gone Plus and again yesterday to see if the pause menu items existed in 105096 for Plus users. I have 100240 backed up as well as all other versions. It isn't obvious to most users that if you have a Plus or Gold Account but using a standard version you will get the Plus stuff like it or not.
Sorting the permissions thing out for non plus users needs correcting maybe I misunderstood but I thought SP1 was the bug fixes from Plus, not changing the layout and adding plus bits, that seems to have been covered with Platinum.
Only way to get a non Plus standard addition if you have Plus and Standard that I can see is with a different Account!
Plus is the only version I can download now as well.