I'm trying to understand the incoming MMS (Multisig Messaging System) in Monero. Reading the MMS User Manual, I am thinking that MMS could improve both the security and performance in the next Monero version.
Is this correct?
Currently with multisig transactions, there is a fair amount of user interaction and the need to send files outside of the Monero wallet between participants. MMS moves all the interaction commands into the wallet and all the communication to Bitmessage, thus a secure channel of communication.
Will the Multisig Messaging System improve Monero security and performance?
It provides a secure way of transferring multisig files between participants, not more generally improving Monero security. Performance wise, it's probably right now slower than other ways (due to the PyBitmessage setup overhead). But it's worth remembering, this is just a first [big] step to overall improving the multisig experience.