A new bitcoin improvement protocol was proposed on the bitcoin-dev mailing list.

I have written a new BIP describing a BIP32 derivation path that supports a single or multi-signature and multi-coin wallet from a single master seed. It combines BIP44 and BIP45 and adds in a self-describing structure in the derivation path for multiple multi-sig combinations within the single wallet along with an extended public key export file format for public key distribution between parties. I can particularly see this being useful for multiple Lightning Network 2of2 accounts for different payment channels.