While I tested less than I would have liked, there are some notable results:

- Green wallet segwit v1 send resulted in funds being sent to the wrong address (bc1qmfr3p9j00pfxjh0zmgp99y8zftmd3s5pmedqhyptwy6lm87hf5sstpn3we instead of my intended destination, Pieter's r5n8 address. You can see this with Rusty's test transaction as well: ef1662fd2eb736612afb1b60e3efabfdf700b1c4822733d9dbe1bfee607a5b9b Blockstream is aware of the issue and has fixes.

- Blockchain.com's wallet behaved similarly, sending to the same, incorrect address. Rusty's blockchain.com transaction for reference: 64b0fcb22d57b3c920fee1a97b9facec5b128d9c895a49c7d321292fb4156c21 I will be reaching out to Blockchain's team to let them know about this.

- Blockchain.info's explorer suffers similarly, "Unable to decode output address" when viewing a tx with v1 output, and inability to display address details for a v1 address

- Bitgo accepts a v1 send address, but then a “Server error” during send occurs

- Coinbase (web) reported on final step of sending: Your send failed Please enter a valid email or Bitcoin address

- brd sends successfully to v1

- bitrefill, casa, xapo, wasabi, all previously failed address validation, and still fail address validation

- binance, bitmex, kraken, all previously failed address validation, but now accept v1 addresses. I did not attempt full send with these services, simply passing initial validations.

- While Riccardo noted that Aqua successfully sent to Pieter's address (b48a59fa9e036e997ba733904f631b1a64f5274be646698e49fd542141ca9404) Ive been informed Aqua has disabled send to v1 addresses for now.