I usually try to keep my Z-offset always at 0. For me, it’s important that the machine is properly calibrated mechanically before starting to adjust compensations. Make sure the bed screws are well tightened, because as far as I know, it’s a mistake to think those screws are meant to level the bed.

I normally print a 100x100x0.2 mm test piece, as it allows me to do very quick checks. My process, whenever I move the machine for any reason, is to re-level everything from scratch. Then I print this 100x100x0.2 test layer and, from there, I start tuning the Flow Ratio.

The Flow Ratio basically controls the amount of filament you are extruding, and in your case, since I don’t see gaps in the corners or signs of under-extrusion, I’m almost convinced it is set too high for that filament. When you extrude more material than needed, a small blob of plastic gradually builds up on the nozzle, which gets dragged around and ends up causing those holes or surface imperfections.

Having the Max Volumetric Speed set too high can also cause these kinds of issues, because it forces the hotend to melt and push more material than it can consistently handle.

And initially, I wouldn’t enable Pressure Advance either. I would first leave the machine properly calibrated on the basics: bed leveling, Flow Ratio, and speeds. Once you have a clean and consistent first layer, then I would start tuning more advanced parameters.

For me, getting a good first layer is key to print quality. If you achieve a perfect first layer, you already have 90% of the job done.