I think so, but remember you are limited to 48 channels with the model 1. The model 2 & 3 have 1000 channels and a model 3 w/FPP is very convenient. I use XTS5k VHF and UHF model 3 in their own XTVA's.
Wait, do you mean the O3 control head? If so, I do not believe the XTVA supports that. The XTVA does support the W3 control head. Hell, the O3 control head costs more than two XTS5K model 3, plus an XTVA and the W3 control head for each.
If you heard/read that the XTVA (Convertacom) supports the O3 you are sort of close as the
XTL5000 will support the O3, after some TIB changes and sacrificing a chicken. I still use a W3 control head with my XTL5000 as well.
W3 HHCH