It’s a hard question to answer, if you should look into it or not. I’ve had a play now and the old Marlin seems slightly better with 2mm per arc. instead of 1mm, and the new Marlin seems better when set to 4mm. I have not connected my pen up to see what 3mm-Diameter circles look like (which is something I would cut often for screw holes) but if they turn out round enough I’d say go with those settings. Alternatively, if you do see what I’m seeing (which no-one has confirmed yet, to my very slight disappointment) then a report to the Marlin programmers might be an idea. At least I know my mods. to Marlin are showing the same issues as your new firmware release, so thanks again!