This has become a lot more complicated than it has to be. Keep it simple.
This all started with someone complaining about performance on conventional frequencies or I think it was specifically VHF. We spoke of grouping conventional frequencies together that require the same filter. You would then go into department options and apply that one filter to the group of conventional frequencies.
I mentioned that NOAA Weather Radio on the 162 megahertz range did not work at all for me but when I applied IFX to each one of the NOAA frequencies it was like night and day.
Correct, you add it to a single conventional frequency. Either it'll do nothing or it will help. It is a universal application and will then be applied to that frequency anywhere in your radio it exists, even if it was part of a trunked system somewhere else in your radio.
If you find your radio is deaf on a conventional frequency that other radios pick up well, press Channel and hold on that one conventional frequency and toggle function 7.
I personally like to make changes on the radio itself. More control, less time-consuming. It's important that when you do hook up to your computer again the first thing you do is transfer the data from the card to Sentinel so any changes you made on the radio are kept.