What Am I Looking For Here?

Anycubic Kobra Max, hundreds of hours printing over the past year, few problems... Just put in a 0.6 hardened steel nozzle to try out. Upped the temp to 210 (from the 205 I was using with the brass nozzle). Printing in pla+, nothing fancy.

Bed was releveled, Didn't seem like z axis set well though, nozzle was still dragging on the bed slightly, so I've been upping the Z offset manually to try out different things.

These two boxes were printed at the same time. - Y facing sides were relatively smooth, but +Y facing sides both had this wavy looking thing going on. Similar effect present on other prints I did post nozzle change.

What am I trying to diagnose here? Vibration? Temp? Flow? Does this look like an effect anyone can say "oh yeah, that's caused by (insert setting here)"?