So, I managed to change a setting somewhere late last night that had some interesting results. Everything would be properly proportioned on the screen, but the outputted gcode would elongate everything by about 15-20%. Circles turned into ovals, and squares into rectangles, etc.
The only fix I could find was to fully remove and re-install lightburn. After that, all was right as rain.
For the life of me I can’t remember what I tweaked, but if someone might know what might have caused this so I can avoide it like the plague. Maybe test and then avoide, but ultimately avoide.