I've tried installing two different versions of the webserver, 2022 and 2024, in different directories on the same computer. It's just the standalone executables, without IIS or anything. I was even able to set up shortcuts for both.
FlexSim WebServer 2024 still works fine (I installed it first), but I couldn't get 2022 to work. I don't know if it's because 2024 was already installed and there is a conflict with having both, or if it's a separate issue with 2022. The command prompt will appear briefly for 2022, and then die quickly. I feel like I've seen a similar issue before on an older version of the webserver (maybe 2022?), on an older computer - maybe with a component not installing or running correctly. But I haven't had a chance to troubleshoot it at all.
If you do want to try doing something similar and it works for you, you should be able to open either version just like they are two separate applications.