CurrentOut PWM Frequency should allow Variables to be used as values

I'm designing an IQAN program to control the test stand at my company. We have a set of seven types of valves that we will actuate using Deutsche Connectors attached to the sections, and potentiometers varying the output. The different valves that we will be testing require different PWM frequencies, so I went into the COut dropdown window and found the PWM Frequency property, which has a range of acceptable integer values from 25 to 335.

I wanted give the user the ability to select which valve was being used at the time, and change the frequency of COut, so that any deutsche connector could be used for any any valve. I started creating a nested set of timers to simulate a PWM duty cycle, but eventually I dropped it and settled for dedicated output ports for each valve, on the grounds that the better functionality wasn't significant enough to warrant the investment of time and energy.

However, the improvement would take almost no time or energy if I could simply set the PWM frequency of the COut pins to the value of a variable, rather than a constant. I can see no reason why this should not be possible, and it would make ideas like this one easier to implement.