@DanOstergren My desktop PC is an HP Omen Gaming box, Windows Pro 11, Intel(R) Core(TM) i7-10700K CPU @ 3.80GHz, 64.0 GB Ram, 4TB internal SSD, 2TB Samsung thunderbolt SSD, Geforce RTX, 10TB external HD, GeForce 3060 Ti with 12GB on board ram GPU, No problems on speed with AI or masking until I started stacking purchased presets randomly. Those presets are heavy AI oriented. I found out later that there is known issue with AI mask layers unless they're added in a specific order. Per the service bulletin that came out late last year, it's important to follow their "Best Order" of develop operations to avoid unexpected results and slow downs.
Per the bulletin it's important to perform editing in the following order to keep the constant updating of masks down. Basic panel edits like Exposure, Contrast, highlights, shadows, white/black point, curves
, clarity, saturation etc. can be performed first then:
Denoise,
Raw Details, Super Resolution
Reflections Removal
Distracting People Removal
Generative Expand
Generative Remove, Content-Aware Remove, Heal, and Clone
Lens Blur
Lens Profile
Crop and Transform
Adaptive Profiles
Global Adjustments in the basic panel
Masking
AI generated masking
Also there's a warning that loading to many presets into Lightroom Classic (whether created by you or a third-party) can reduce performance because the Develop module generates thumbnails in the Navigator panel for each preset. This is most strongly seen once you have 2,000 or more presets. Reduce the number of presets loaded into Lightroom Classic to only those you use most often to avoid this type of slow down.
Once I followed the above the problems went away. However, I don't really use the purchased presets that much because, I find they don't really save any time, as they require a lot of manual tweaking.