One thing to love about VCarve is it doesn’t have the options to pull in these special-use functions. It does the simple movement stuff only.
The postprocessor should not be dealing with tool offsets or variable fixtures. Just the preamble for explicitly setting modes (like inch file), usually T1 M6 to specify “this is tool 1”, M3 S18000 (start spindle CW at 18K rpm), and M8 (turn coolant on, pointless as we don’t do coolant, but it’s traditionally there)
G43 establishes a tool length that shifts the Z coordinates for that tool. That’d be for an ATC, where you have different tools in mounts, grab one and say “this is 1” longer than the others, so when the code says go to Z= -0.25, you actually want to go to Z= +0.75. Not approp.
G49 cancels the tool offset. VCarve’s preamble in all g-code files includes a G49 to get us in a known state.