Lee,
You are quite right of course. If you have buttoned down a way that works for you, gives you full max flash without overspill into fog, each time based on experience - that's perfectly fine. If it works, it works. That's what counts.
On the other hand, I have often read people describing on line a method of giving a bit of exposure through some diffusing material in an arbitary fashion as being the way to pre-flash. It's not. It needs to be done in a precisely measured or calibrated fashion to get predictable, repeatable and fully effective results without fogging. It's not remotely difficult but like most things in printing, it needs to be controlled for optimum results. (I'm making the assumption that we all want optimum results of course

)
Henry
Apart from Dave, no one has answered your question yet, so here is my 2p worth.
I would like to start by saying that I am a fan of RH Designs, I use their pro stop clock and I often demonstate it on B&W workshops and everyone immediately wants one! I don't use their paper flasher because I have 2 alternative set ups that I prefer.
I have tested it and I did find that for my use there were drawbacks - not major, but it didn't offer me an advantage to what I use. This was mostly due to siting of the unit. If flashing the paper in the easel the flash light source needs to be in the lens axis otherwise 'shadow' artefacts may occur. A light shadow may appear next to the edge of a masking frame or blade, or a reflection may be thrown onto the paper from an edge of a 2 blade frame. the 1st will give a light 'shadow' (unflashed), the 2nd a dark shadow. These are more apparent with some masking frames than others (I have quite a few, generally 4 bladers are better)
I also didn't find a really happy place for it. My ceiling was too high and anyway the unit had to be significantly off axis to avoid a shadow of the enlarger head. Applying it to the lens mounts with blue tac or similar tended to all too easily give alignment discrepancies from pressing it into place, which I am slightly paranoid about.
I run 2 different flashing systems, both from my stop clock, which are very reliable for different purposes, and give me everything I want, so I don't use it.
However, I also know that many people use the unit and love it - so hopefully some will now chip in and counter my views

Hope this helps.
Tim