I have a Benjamin hand pump and a much cheaper chinese pump. I think the chinese one is a much better buy. It has a little cotton filter providing some moisture collection. I think it is OK for filling a gun (although with a big carbon fiber tank you might need to check it while filling). The Benjamin has no moisture filter. I was OK with hand pumping my first PCP, a Prod. About 30 strokes would fill it. But my second was an Avenger. It only stores 180cc of air but that is almost 3 times as much as the Prod and it can store it at higher pressure. So it took hundreds of strokes to fill the Avenger which was not much fun. Very doable but I only filled to ~4000 psi once or maybe twice. Mostly I filled to 3000-3,500. It takes increasingly more effort to make a stroke as the pressure increases. I would not even think about filling my 45 minutes SCBA tank with a hand pump. It would take practically forever.
If my Yong Heng fails I will try rebuilding it and will hand pump my guns while I am doing that. If it gives indications of failing I will buy the parts ahead of time. But if it fails without warning I'm not sure I will be patient enough to wait for Alliexpress deliveries of the parts. I may just buy another YH or maybe one of the little more portable pumps. I can hand pump, I have done it. I still have my pumps but I know from experience that I do not enjoy hand pumping.
I see hand pumping as not at all useful for filling a bottle. I think it can work for filling even a larger air capacity air gun but only if you are pretty patient or determined. It works best IMHO for smaller air capacity guns that do not take hundreds of pump strokes.