Hey everyone,
I noticed that this old thread was getting comments again.
@Coincart’s problem seems to have been resolved, according to their tweet here saying they’re offering ZEC.
Details on this plugin can always be found here.
Furthermore,@artkor says there are now 7 merchants using the BTCPay Zcash module. Which is great; I’m so glad that the BTCPay Zcash module got fixed.