Many subfiles could be much more reusable as modular building blocks if they contained some way of fixing the position of some elements. For example the interior/underside of many bricks. 76371s02.dat is a good example. If the hem was removed and the 1 LDU offset of the inside notches could be retained from scaling, this part could be reused for any box height, including the 0.25 scaling factor needed for many parts. What about a command that would fix the position of one end of an element?
0 FREEZE -y end relative to -y boundary
1 16 20 49.5 16 1.5 0 0 0 0 45.5 0 -4 0 box4-1.dat
The above code would result in that the 1 LDU offset (counted from the -y direction) would be retained in all scaled versions of the modular subpart.
Another option would be to define variables and then scale the variables rather than the file.
0 FREEZE -y end relative to -y boundary
1 16 20 49.5 16 1.5 0 0 0 0 45.5 0 -4 0 box4-1.dat
The above code would result in that the 1 LDU offset (counted from the -y direction) would be retained in all scaled versions of the modular subpart.
Another option would be to define variables and then scale the variables rather than the file.