Scaling factor (scale/scalem) and scalefactor

Hi all,
I have a confusion regarding scaling factor provided like the following capture in ADE explorer 
As stated in the document below the scalefactor is for foundary to scale devices indepedenntly with designers (using scale/scalem) 

.- so i wonder, if foundary they already use a variable named something like scale_m = 0.9 in their model file --> in this case, if I apply scalefactor = 0.9, scale=scalem = 1. How does it affect to simulator and simulation result? 

.- second thing, if I apply scale = 1, scalem = 0.9, scalefactor = 1, in this case, given my transistor length = 1u --> does simulator scale my transistor length to 0.9*1u? or it only scales the devices whose physical dimensions are in meter unit only? 
.- and last, if i apply scale & scalem at the sametime like scale = 0.5, scalem = 0.9, does simulator scale my TST length to 1u*0.9*0.5? 

Greatly appriciated if someone can clear my doubts,
Thanks,
Tommy