@mably thanks for linking through to this, and @manfredkarrer thank you for your patience. Sorry to hear about the issues you’ve been having. Transaction proofs work with wallet713. I’ve just pushed an update to our documentation that explains how this transaction proof can be generated and validated by a third party, please see here: https://github.com/vault713/wallet713/blob/master/docs/usage.md#transaction-proofs--grinbox-only-
Note that this functionality only works on a (recently built) wallet713 and on transactions using grinbox addresses.
We’ve been really busy this week due to conferences but we’re hoping to have updated binaries soon. Any questions please let me know.