Hi Jim,
The issue is not of a "mismatch" as you describe, but, rather of the correct (rated) load the QCX apparatus has to see to work as expected.
If we take your example of a DC power supply, for a given voltage it has a maximum current it can supply (out of damaging or having protections tripped), which in direct current is very elastic, whereas in RF is more narrow as open circuits can change the amplifier behaviour to risking of damaging it, or if the load is too reactive put the operating point of the amplifier in a non stable condition, etc.
So looking for a loading that is appropriate to the QCX as per the designer is a sane approach.
IF the power amplifier down the signal path has enough gain, another solution could be attained using an attenuation pad which would load the QCX better and put enough signal to the amp to work adequately, but for such scheme we would need additional data.
