I'm not interested in dodging and burning at this point.
Unless you are totally in control of your scene's illumination, you will likely need dodging and burning.

The literature suggests that a grade 2 or 3 filter will cover most printing needs, but my results with these always seem to be flat.
Don't trust "the literature"

As such, I find myself using the grade 5 filter more often than not.
Increase negative development by 25%

I thought grade 5 was for slightly more advanced techniques -- like spilt-grade printing -- and not really to be used by itself.
You thought wrong.

Even so, I'm not completely satisfied with my grade 5 prints.
See above (Increase negative development by 25% and use dodging and burning).

So I've done some more reading and came across some threads and this link about calibrating your enlarger's color head for variable contrast printing:
That is a good technique, but Ilford already did it for you if you use Ilford papers (see the chart they put in with all their paper packaging). Realize what is going on with the 'calibration.' It allows you to change contrast and keep your exposure for middle grays constant. It does not make your final prints look any different, it just saves some steps getting the exposure correct.