Nikon NIKKOR Z 14-30mm f/4 S Lens

This lens has significant barrel distortion, but it is easily and (in some cases) automatically corrected with photo software like Photoshop.

1.07 lb / 485 g

This will really depend on the lighting situation. F4 is not the fastest Lens, but the Z6 has In body Stabilization, which will help a lot in low light situations. Also, you can bump the iso up pretty high with the Z6 and have acceptable image quality. The only thing you will lose not having a faster lens is a shallow depth of field, but this usually doesn't matter much in an ultra wide and typically you will want a larger depth of field for the photography people tend to use this type of lens for.

Vignetting would be minimal on the Haida. It would depend how close you look and also if the background is lighter or darker. The Nisi V6 and Haida M10 are very similar though, they have differences in the locking mechanism which I believe is what you are referring to, but both are easy to use in my experience once you get used to it. I don't see that it would improve your ease of use much by going to the Haida M10.

I don't have a Z50 but this seems like an odd lens to buy for a DX body. You lose the ultra-wide nature of the lens which is what you are paying for. The lens becomes a 21-45mm lens on a DX body. You are better off buying a wide angle DX lens specifically for your model like the Z 16-50, which is also a lot less expensive. But to your question. This isn't a heavy lens. If you shoot at 1/50 or faster you should be fine. If you are wanting to shoot at slower speeds, then yes, I'd use a mono or tripod with a Z50.

this lens takes 82mm filters

The minimum focusing distance is 11".

I love this lens, but this is a "focus by wire" lens (like all other S lenses so far I think, except perhaps the 24-70 f2.8), which means it's great for quiet video autofocus, but for manual stills focusing it's pretty bad actually. There's a very slight delay, when turning the programmable ring, and seeing the focusing effect through the viewfinder or rear screen. It's actually pretty terrible for precise manual focus, but that's the case for all such mirrorless lenses that focus by wire. Also, the resistance is extremely slight, and the effective focus throw is rather short. So it's terrific for autofocus and especially video, but not great at all for stills manual focus imo. The ability to zoom in through the viewfinder does help a lot. If you really want a direct manual focus lens, buy another one, but none will provide the quality, focal lengths and light weight of this one. It's pretty spectacular all things considered.