Hi,
I am suggesting that as you around london you may be able to get a Home Demo from JB or HOS at MFA, if it's on their way and such.
I think I'll pick up as the Technician for the UK distribution.
It would be fine with long cable runs as well. The TVC merely passes on what your source puts out. If your source can drive what comes after the TVC, then so can the TVC... ;-)
I would not think that length and number of cables would be a problem. The problem would be to make a unit with 3 pairs of XLR Outs! The MFA PMP has space for 3 Pairs of XLR's, so you would give up all XLR inputs to get so many outputs.
Ciao T