I have now purchased and received the MF2. The muck stick is backordered. I have been using a pair of YS-D1's since 2015, and in June 2022 I first tried the MF1 with (and without) snoot.
I dove with one YS-D1 and one MF on 20-30 dives, giving me the option off having at least one big strobe for whatever might come up. I was shooting with 105mm macro lenses though, and I don't think I ever used the YS-D1 in conjunction with the MF. I used it a few times when I wanted a bit more oomph.
The miniflash isn't suited to wide angle work. It's just too small. Not sure the beam spread, because I used the YS-D1's any time I needed wide angle. With the 16-35 or 14-30, I simply didn't bring the MF but instead used both YS-D1's.
SO - the MF is really suited to macro work, and for that the small size is an advantage. Limited power might also be useful in that you are much less likely to blow out the exposure with the MF than the YS-D1.
On the MF2, one major new feature being advertised is a stronger focus beam for lining up the snoot. That should be quite useful as it can be hard to see the aiming light when the sun is out at shallow depth.
About the MF2 - it did not come with a battery. Keep that in mind when you order. It also did not come with the filters (IR or gels) or filter holder, so you have to order some accessories to use one MF to trigger the other with an IR signal.