Gotcha, I see how that can complicate it.
Are you able to use a velocity systems (formerly mayflower) low-pro cummerbund on your soft vest? They make low-pro elastic cummerbunds with pouches built in. I use it on my overt vest and carry my baton and radio in them to keep them tight so I don't have them hanging off the outside on pouches. Even if they don't make that cummerbund any longer, you could still buy the standard low-pro elastic one and mate some BFG ten-speed pouches onto it. Even if you were to get your radio up there off your belt, it could help free up some space.
It sounds like a VS LPAC would be a great option for the work you're doing, but given your restrictions on gear if you can make the cummerbund work with your current soft vest then that might be a workable compromise.