Edit : Basically (if I get it right), you can make a multisign Bitcoin address using the command line (but no user-friendly GUI). And to spend funds from this address, many seperate people have to sign the transaction. So this is not as simple as sending a transaction from your computer. Some work still need to be done on this part.
I also suppose this requires manual utxo hash selection, right?
Not sure about this, but today one of the easiest way to use multisig (that I know of) is Electrum.
But in my case, this is for zcash. And since zcash core has the same rpc as Bitcoin core.