I don't have the depth of experience with this to by able to offer much, other than saying what you are proposing sounds reasonable and safer, so I encourage you to go forward with it.
On a general off topic note about MUC - since you seem to be working the most in this area, my personal feeling (without actual technical analysis) is that if we should be doing anything, we should actually be reducing the feature set of MUC and only allowing developers to do very performant operations with it. Anecdotally it seems there is so much functionality that many people don't know how to use and too often we are coming across MUC uses which are utilising its 'flexibility' at the cost of performance (e.g. serialisation impact). On reflection I think it would've been better to restrict the way which data which can be stored in MUC so it was as fast as possible rather than as flexible as possible.