You know, you seem to have put together a really mightly impressive combo there with the Tamron 17-70mm f/2.8 (if I'm not mistaken) and the Sony A6400, still one of the best compact ILCs in the market; the lens alone is a strong argument for staying within the E mount ecosystem! So there's really no immediate reason to crave a Z 50 ...
That said, I'm truely enjoying mine - you can't fault it for a compact, high-performance camera, and it's much nicer in the hand and in use than my Sony A6000. It put an end to my considerations of upgrading the Sony ...
@theoldsmithy Martin, is it possible you thought of Mike (Thai-Mike)?
M.