While I haven't installed the bolt hold open device on my own 10/22, the fact that it is completely modular, and very easy to take apart and put back together would suggest that it cannot be a very difficult mod.
Personally, I'd rather my bolt close than deal with proprietary mags or messing around with the factory ones to make them work with the proprietary solution. The 10/22 is designed so that dry firing it doesn't actually harm it in the same way dry firing many other rimfires does. I tend to subconsciously count my rounds out of the 10 round mags, but I have dry fired several times with my 25 rounders, and I no longer concern myself about it.