That Grand Seiko Quartz I’d ordered was delivered today, and I’m very impressed with it, yes not many would spend a reasonable amount on a quartz watch, but it does look ( imo ) really nice, appears to be well built, and its 9F movement is supposed to keep very accurate timing, it’s also extremely comfortable.
Now that I’m very happy with the two watches I have ( one that’s been a dream of mine ), I don’t think I’ll be getting anymore, but time will tell, pardon the pun. 🙂
I've used a bunch of MKDSN 5.08 spaced from Mouser, they exist (for example 651-1729131).
Also, note that the 400V is its CAT III rating (see data sheet).
The CAT II rating, which is more relevant for an amplifier for home use, (think broadly home appliances connected to a wall outlet) is 630V.