I use a different instance of OBS for things that are different enough that a single instance can't do it well. The potential pitfall there, is if your system doesn't allow multiple things to access the same resources. Historically, that was true for everyone for performance reasons. Some systems have lifted that restriction now; others haven't yet.
The "standard" way to run multiple instances on Windows seems to be to use one native instance and then a separate portable instance for everything else, which is a lot of duplicated files.
The better way to do it, at least on Linux, and I would imagine Windows and Mac too, is to use the --multi flag on the command line. Modify the shortcut, launcher, or whatever you call it, to put that on the end. You might also want to use --profile "Profile Name" and --collection "Scene Collection Name" to load different settings for each instance. The quoted names must match exactly, and anything with spaces must be in quotes, or it's as if you didn't include that option at all.
Use the --help option on the command line to see everything that you can do there. You do have to do that in a terminal (Command Prompt for Windows). A shortcut won't show you the response.
