PLA first layer - variations across print bed
I used the "live z adjust my way" g-code and felt like I had a pretty good live-z value. The calibration square looked good. I got it within about 10 microns of starting to feel the rough surface from the nozzle dragging. I'm using Prusament PLA, jet black, with the default Prusa Slicer settings.
What I noticed yesterday while printing something that took up nearly the entire bed was variations in the first layer across the print. In some cases, the first layer melded together really nicely and you can't see the individual lines (2nd pic). But on other parts of the print, you can see the individual first layer lines. (1st pic)
Do I need to do the advanced calibration, adjusting the live-z value across the head bed? Or raise the bed temp a little for the first layer?