If the CPU usage you are referring to is the one in OBS Stats window... well, not really all that meaningful in my experience
What you need to know is overall system CPU usage (ie from System Monitor or similar)
And, your description would indicate your system is fine, EXCEPT when using the 3rd party Move plugin comes into play, so either it is overloading the CPU, or it has issues on the new Apple M-series CPU and is in need of optimization (in which case, ask plugin author)
If CPU being overloaded, then could be plugin fault, or that you are simply running near maximum stable utilization before using that plugin, and its use puts you over the top. In which case, all the system optimizations apply (reduce background and overall CPU load, such that plugin does NOT drive system to overload). But if plugin is problematic, that may not be possible to free up that much spare CPU resources... I can't tell you which... that is for you to figure out
With decades of IT experience... I'm not underestimating the M1... it is great at some things... and really _not_ at others. And you are playing with code long written for a X86 code base and only recently being re-coded/compiled for new Apple ARM SOCs (M CPUs). And free, open source tends to take a while for optimized, stable code to be released for new environments, so patience will be required when using a M-series based system with X86 based applications, and in this a 3rd party plugin