@User In the sky130A.magicrc file supplied with the skywater pdk, at the top, appears the following related to the grid size:

# Put grid on 0.005 pitch.  This is important, as some commands don't
# rescale the grid automatically (such as lef read?).

set scalefac [tech lambda]
if {[lindex $scalefac 1] < 2} {
    scalegrid 1 2
}

Does setting a user grid different to this break anything?