I'm understanding that the 2017 and most recent group buys that included the taps for the Bock housings yielded Bock taps that have not worked. This was brought up after the 2017 group buy, but few weighed in on the thread where it was discussed. I don't know whether the 2020 group buy had an issue.
This isn't a criticism of the organizers, but I think we'd be wise to pause any other group buys on the taps for the Bock housings from Tapco until this is resolved. I participated in the 2017 group buy, but I confess that I haven't used the taps to know whether there is an issue with mine.
I'd think Tapco would want to know whether their product isn't of sufficient quality/tolerance to work. At a minimum, I think we should always take Phil Dart's advice and send a housing in advance of an order to make sure Tapco's effort is suitable.