Real Apple SoC M1/M1 Pro/ M1 Max support

Premiere Pro doesn't really seem to use 100% of the available Apple SoC power. Has Premiere really been fully programmed to work natively on M1?
Even though the M1 Pro has dedicated H264 encoders/decoders the playback is lacking sometimes. The sad story is that for some time it's totally fine but then after a few minutes it's starting to slow down...