XY SIZE COMPENSATION - UNITS
"xy size compensation" should be in mm/mm like thermal expansion. otherwise it has to be adjusted per part size and only works on symmetric parts.
RE: XY SIZE COMPENSATION - UNITS
XY size compensation value, IS a crude tool which enlarges or reduces the XY Dimensions of an artifact by the given amount. this is not a ratio based tool. and it is not selective ie, you cannot choose to increase only the X dimensions or only the Y dimensions. the tool works on any 2 dimensional artefacts in the XY Plane, the artefacts do not have to be symmetrical
If you would like a thermal expansion tool you would need to communicate your idea to the developers via the Prusa Slicer GITHUB Page, proposing how the tool would integrate with Prusa slicer.
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: XY SIZE COMPENSATION - UNITS
It would be nice to have it a % scaling factor that can be stored as part of the filament profile. You really need to scale the part because shrinkage causes everything to move.
By doing this you can compensate for different shrinkage amounts for different materials.
I'll add though that the physical size you print something is only a small part of compensating for shrinkage. There are so many variables involved like warping, extrusion multiplier, number of perimeters, infill, #of top and bottom layers etc., and if you print large parts like on the XL you open a whole new can of Worms because large parts magnify all of these affects.
If your printing figurines it probably is not critical, but for functional parts these things become important.