I don't know SP or how its shortcuts work, but did you check if you already have those shortcuts assigned in plasma's global shortcuts? The easiest way is to assign them to any plasma global shortcut and see if it tells you there's a conflict.
If that's not it, can you trigger those SP actions with an external command? Then you could do it through plasma global shortcuts.
As far as I know, SP is an electron application and if you run Plasma in a wayland session, global keyboard shortcuts won't work, unless you enable it in the Plasma settings.