You can't run two *installed* versions on the same machine, but you can run one installed version and as many portable versions as you like, or you can run everything portable (but I wouldn't).
You can use NVDA Remote with 2019.3, but you have to get the compatible version of the download, see the NVDA Remote Access Download Page.
Brian - Windows 10 Pro, 64-Bit, Version 1909, Build 18363
Science has become just another voice in the room; it has lost its platform. Now, you simply declare your own truth.
~ Dr. Paul A. Offit, in New York Times article, How Anti-Vaccine Sentiment Took Hold in the United States, September 23, 2019