I discovered something else very bizarre. MERELY REFERENCING A VARIABLE NAME CAN ALTER THE GCODE. In other words, you might think that if your toolchange_prime_distance is a certain number, then you can type that number, or type [toolchange_prime_distance], and either way, that number will get inserted into the Gcode. And that generally works for that immediate variable reference. BUT ...it can cause the slicer SW to behave differently later. In other words, it "remembers" the fact that it resolved the variable name, and that memory might cause it to do something else.