Combine Virtual Desktops With Plasma Activities
The way that KDE sets up activities is clumsy and weird. An “activity” is a group of plasma widgets that you can switch to by “zooming out” of your current desktop and “zooming in” to another.
Probably depends on how many plasma objects > you can have running at once The upper limit will always be RAM (system resources)
--as soon as the number of instances exceeds the amount of RAM (+swap) available to that application, it will hang
If you know how much RAM is being used by the application while running for one instance, you can guesstimate how many instances that you will be able to run, that will be your theoretical maximum
No point in searching unless the Kde developers have limited it in the application settings or you have applied quotas against your users (also limiting access to system resources, storage space or RAM )