As someone in the UK, I've had my share of the highs and lows of ordering from China and from the USA, so it's nice to see someone producing high-end acrylic CIEMs in the UK, David!
As far as the nonsense you've just experienced on H-F, it comes as no surprise to me. I've long said that the owner of that site is an out-and-out narcissist, who seems to surround himself with 'YES-men' to collectively ride roughshod over the rest of us mere mortals. Ironic, because he appears to lack the intelligence to grasp the fact that without the mere mortals who use his site, there wouldn't BE any site, no sponsors, no advertisers, no income, no ivory tower...
No matter.
If the C4 performs well, you may be certain that plenty of us will mention the C4 all over that forum, so you'll have the last laugh ;-)