I'm still not clear on why (or if?) that would be. When the pressure is reduced, the temperature will drop due to the throttling process, but the lower pressure steam also has a lower saturation/boiling point. The only thing I can think of is that if the loss through the throttling valve is too much, some steam will have to condense.
But typically, the opposite problem exists: when hot, pressurized condensate goes through a throttling valve, some will flash to steam.
Here's a diagram of a PRV station that does not include a condensate connection at the PRV. Certainly it would at the risers, but because it is at the low point of the system. I'd think if condensation was an issue, it would be collected at the valve itself.
http://www.forbesmarshall.com/fm_mi...d=156&s2name=Steam Pressure Reducing Stations
In any case, the OP mentions the pressure after process equipment. Worst case scenario is low flow, where pressure is constant everywhere that doesn't have a valve shutting it off. So any steam trap on the system will have condensate at the same pressure as the steam. During normal operation, valve and fitting losses drop the steam pressure and therefore the condensate pressure a little, but that's not what you design the pressure requirement for.