Update, one year later.
Since it's a stereo compressor I've dedicated one side to the recording feed. My recordings are now almost completely even in volume. I'm recording using Reaper for the moment. I had originally looked at reaper because I wanted real time compression on the recorded signal. That works fine in software, but I had to set the input level rather low to prevent clipping the computer input.
Now, with the external compressor hooked up, I can increase the level of the input signal. I still use the software compressor to flatten down the peaks, but it kicks in rarely and not very hard.
The other side of the compressor I have dedicated to the pastors lav channel. I'm using the wired lav (the pastor has gotten used to it). I don't push this compression very hard...around 4-5:1 and kicking in about 40% of the time.
Still numerous problems in the system due to abysmal acoustics, but I'm happy with the compressor.