Payjoin boards are now available in Bark and enable a wallet app to receive a Payjoin and board onto Ark in the same transaction, saving the user fees and time. The same trick can also be used to on-ramp onto a Cashu mint running Bark, no channel management required. It may also be the first example of Transaction Cut-Through bitcoin has seen, a 13-year-old idea from Greg Maxwell!
More details on the blog: 
Second
Board Ark (and ecash mints) with Payjoins | Second Blog
Payjoin boards are now officially supported in Bark. As of version 0.6.2, a wallet app can receive a Payjoin and board the proceeds into an Ark in ...