It is important for getting a comfortable shave that ones beard is sufficiently softened to make the hairs cut easily without pulling and associated irritation. Whatever means works best for you in practice is OK.

I find it easier to get a close comfortable shave if i wash then shampoo my beard in the shower immediately before shaving. It is important to prevent the beard from drying out before completing the shave, or it will get harder to cut and the risk of irritation increase. I reapply lather or water as needed during shaving to keep my beard soft.

If I cannot take a shower, I wash my face at the sink with warm water at least twice to remove oils and soften my beard and then lather. This does not work as well for me as a preshower, but I can get an OK shave with no or minimal irritation. I have not tried Kyles prep, but i can see where it might better soften a beard then a simple 2x wash with warm water.

It is beneficial to also use a lather that allows the razor to slide easily over your skin and that provides some protection. I like MWF.

One should strive to find a gentile razor and blade combination that, if possible, removes the beard with a minimal number of repeat strokes over the same area. For any given razor/blade combo, the risk of irritation increases with the number of passes over the same area of skin.

There is a balancing act in choosing whether it is better to use a more aggressive blade/razor combo which may reduce the beard with a minimal number of strokes but possibly be more traumatic on the skin verses a mild blade/razor combo which may be less irritating, but requires a greater number of passes over the skin.

There are many variables simultaneously at work during a shave so YMMV. Good luck on your quest to find your ideal prep, blade, and razor combination.

HTH