KK. Par for the course these days. Metric Taps, Dies and Industrial fixings are cheap, so that's what you get.
A seat I bought in the 1970's had metric captive nuts. Back then UNF, UNC and BSF were the threads in your nut and bolt box, and buying metric nuts and bolts was the new order. So that came as a surprise, I thought I was getting a genuine BSA seat with cycle thread fixings. No, it was an unbranded pattern part along with the others entering the distribution chain as the established major suppliers collapsed and you did not always get what you were expecting. The dealers charged the full BSA price, plus the newly introduced VAT (Sales Tax) whether they were registered for VAT or not..... No change there, then.
There were also nuts and bolts with metric threads and flats to fit your old AF Spanners. A sort of halfway house as the new world of metrication swept away the established thread forms. The auto industry used these, allowing modern threads to be used in production, but permitting the continued use of your old socket sets and spanners. I think we called them ISO Bolts. Talk about confusing!!
Swarfy.