While there has always been several external box solutions for housing TBC's.
I used a extra 2000 and then there is the DPS ES2200 etc.
I think the issue might be the lenght of 50 pin cable from the PAR to the TBC.
If I remember correctly...(sigh) DPS included the shorty cable for the install due to signal issues?
I'm looking for my old manual to read up on the question?