I just tried it on the tcp too. No Dice
I tried this in the top pre walter section
tcp_min_height 300
and it did nothing
I also tried this in the tcp section
set tcp.size.minmax [200 300 400 600]
and it did nothing
So ..... it seems the 1st one (WT's mcp_min_height) only works on the mcp minimum size (no maximum) and it lives in the pre walter top section.
It wont work on anything but mcp minmum size.
the second one (set trans.size.minmax) only works for the transport, and resides in the transport section.
WT, we need just one more clue, something, ANYTHING!