There is no such switch in Thinapp 5.x which will allow you to do this.
Can you suggest a solution or workaround for me so that apps such as Firefox will not generate so many processes visible to the host system (in Task Manager)?
Many end-users, who are tech naive, in our organization are complaining why so many processes are spawning up since we migrated to Firefox 70.x. Some of them would just force close some of the processes because they were taking up too much memory and were slowing down Windows. I am aware that this may be partly Firefox's problem, but I also want to find a way to control this issue using ThinApp if possible.
Expected behaviour, not something you can change and I couldn't see a reason why VMWare would incorporate a feature to show only one process.
Both Google and Firefox do this for legitimate reasons. Even if it was one process it would still be using the same amount of ram, so the users end tasking them are just shooting themselves in the foot.
Google Chrome takes advantage of these properties and puts web apps and plug-ins in separate processes from the browser itself. This means that a rendering engine crash in one web app won't affect the browser or other web apps. ... Basically, each tab has one process unless the tabs are from the same domain.