If the handy were entirely composed of mild steel it might not be necessary. But we are talking about something made out of ABS plastic with what looks to be brass threaded inserts melted into it. Two things that do not naturally go together regardless of the steel or alloy that the threaded insert is made of, at minimum. Agree?
So any off the shelf bracket which is made from thin steel or 3d printed out of your preferred material will utilize one or both threaded holes. To your question. If attached by only one of the two mounting points, scooting over an inch in bed…over tightening the strap for a little more sensation or to mimic the one that got away…poses a tremendous stress load on a single 1/4x20 mounting point. To begin with, that is small hardware. It is just barely out of the machine screw classification where you start referring to them as bolts. Using grade 5 or grade 8 hardware will not change the leverage being applied to the hot nut which came pre-inserted in the Handy2.
Now if you utilize both threaded holes in your selected mounting configuration, you are then ensuring that the Handy2 can handle an axial load.
If using only the bottom hole, a down stroke is leveraging the unit straight back and away from you. An up stroke is doing the opposite. Almost guaranteed to break if the fastening hardware ever comes loose, but even if it does not, it’s a tremendous stress load.
Using only the rear hole below the USB-C Charge/Passthrough port, an up or down stroke is still applying leverage in the same manner, basically prying the Handy backwards and forwards, even if you can’t physically see it happening. Leverage is leverage. A see-saw is the simplest example. Fixed at one point. Fat kid leverages skinny kid lol
So using both is what I highly recommend to anyone looking to source a good hands-free mounting solution. But as I said earlier, if the two threaded mounting holes weren’t essentially right around the corner from one another, and instead closer to top and bottom respectively, then that mount would not only be extremely steady (likely adding to the immersion) but it would also lessen the odds of the brass nut inserts being pulled out. One of the super early bird backers posted about one or both of them being ripped out of his a couple months ago here on Eroscripts.
I am a tradesman with fabrication and welding background, millwright, and a hero to many engineers throughout each passing year. Within a few moments of glancing at a blueprint which the engineer has revised multiple times, I can usually point out two or three things that are not going to work the way they expect them to. I also help them with the solution after being argued with.
Engineers are academically gifted by and large, and they leave school with a hard earned degree. But the best engineers, and they are quite rare…show evidence of working with their hands at some point in their early years. On the farm with grandpa…or just curious as a child and always taking things apart to understand how they work. These are the best kind, as book smarts and common sense seamlessly fit and work together in their minds. 90+% of the 500 or more that I’ve met…I’ve had to explain 3-4 different ways why their idea is wrong. But when the lights come on, I’ve made a friend and established trust. If they do not, I end up doing the stupid thing they ask for to give the better visual…and my smart ass mouth typically has my boss calling later. As Brad Pitt said in Inglorious Bastards…”I’ll probably get chewed out”, “I’ve been chewed out before” 