https://opticallimits.com/nikon/laowa-8-15mm-f-2-8-ff-zoom-fisheye-review/

Apparently there is a zoom fish-eye from Laowa in z mount., although no electronic coupling.

As long as an order can be placed, and the shipment is fast, either site would work. Less than 1 week from ordering to delivery at my door, for a low price, is OK for me

For people reading Japanese, maybe. I purchased my copies using htttps://www.amazon.co.jp/In-English/ and search for Shoten adapters. Very easy.

Hugh linked to an English version of the user manual.

The system logs show sometimes a lot of database errors.  Most boil down to the same thing, viz. users trying to use 4-byte emoji's. Apparently, the MySQL implementation we are using cannot comfortably swallow these special byte sequences.

Another, usually less frequent cause, is external hacking attempts. Mostly these cause the NG server to be responding slowly, partly because the error logs fill up.

A quote from another web site facing similar issues,

Workaround is easy: do not use "emoji" characters.

Fix is very non-trivial, as it requires modifications to the database to
handle four-byte extended Unicode characters, which it doesn't by
default. Three bytes is plenty of every written language in the whole
world, and no-one thought we'd ever need four bytes until Apple picked
up the Japanese craze for emojis!

The last statement reminds me of the infamous "640K is enough" quotation ascribed to Bill Gates. See https://www.computerworld.com/article/1563853/the-640k-quote-won-t-go-away-but-did-gates-really-say-it.html

Having a Z50ii as my only camera I do see 16-50 2.8 as a good choice but 12-28 you mentioned is under consideration even when I had my Z8: a lightweight affordable super wide lens
On the other hand the 16-50 kit lens is not bad,  had it in the past and very satisfied as my only dx lens
Regards

I agree that the 16-50/3.5-6.3 is good enough that the 16-50/2.8 is only an obvious choice if you need the superior optical performance or capacity for subject isolation. That is more likely if, like me, you are DX only, but even then I need the 16-50/2.8 rather than the 16-50/3.5-6.3 only occasionally. The catch is that for those occasions it is hard to see a cost or weight competitive alternative to the 16-50/2.8.

The 12-28 is much better than its weight of 200g and cost of US$400 would suggest. As Birna points out, it has a lot of barrel distortion at 12mm (-15% radial, according to Bill Claff's Optical Bench site) so you lose some peripheral sharpness when that is corrected, but you have to spend a lot more money to do better (eg, at 14mm the 14-30/4 is about -7% at the DX boundary and the 14-24 is about -2%).

The 18-140 is inferior to the 16-50/3.5-6.3 in the overlapping range, so it is the longer focal lengths that make it attractive.