I know Bitcoin Core and Electrum will allow my to
joinpsbts to create a PSBT with the inputs and outputs of both. They also allow me to
combinepsbt to take two PSBTs with the same inputs and outputs and combine signature data.
But is there a way for me to take two PSBTs with
SINGLE|ANYONECANPAY signed inputs and combine the inputs and outputs into one PSBT? The
SINGLE|ANYONECANPAY sighash would seem to make this possible, I just didn’t see this workflow covered anywhere in BIP-174
If Core or Electrum don’t support it, is there a python library that might?