Also, if cpu draws too much power, you will not get the dynamic power boost. Try to limit your cpu wattage. The dynamic boost is up to 15W, depending on how much power the rest of your system uses.

nvidia-smi -pl POWER

This will probably not work with recent driver versions, but might work with 525.

It works when set up with flatseal.

Same for most AMD laptops as well.

I thought compression would not help much with disk space as well. I believe it depends on the use case. After switching to btrfs and enabling zstd compression, my Arch install reduced from 100GB to 60 GB in terms of used disk space. Most of the savings are from documentations of development packages.

If your dGPU supports rtd3 power management, it should (almost) completely power off when not in use. For me the battery life changes a lot: is something like 2 hr vs 10hr battery life with the GPU off, which is very noticeable.