Looking to create a partial signed transaction with pybitcointools that is recognized and accepted by Electrum GUI client. I have tried to do so for a 2 out of 2 multisig transactions, but so far failed get a partial signed transaction with pybitcointools.

With the commands mktx, multisign and apply_multisignatures I was able to create (2/2 signed) multisig transactions, accepted and ready to broadcast by Electrum GUI client once loaded from text.

When using apply_multisignatures with only one of the two multi signatures I expected a (1/2) partial signed transaction that could be imported/loaded into the Electrum GUI client. However, the Electrum GUI client didn't recognize this transaction.

How to apply only one signature with pybitcointools in a way that is compatible with the Electrum GUI client?