Matchpoints is a strange game. +430 beats +420 as much as +980 beats +480. This causes unique concerns for bidding in the context of matchpoints.
A problem faced by my opponents illustrates the concern well. Opener had started 1♥ and received a 2♦ response in an uncontested auction. Opener raised to 3♦ (not my call, but a fair call) and heard 3♥ setting trumps. After 3♠ from Opener, Responder bid a serious 3NT. Opener finished the auction by bidding 4♥. My partner, of course, elected a club lead from Qxx(x) instead of a spade from J109x(x) [I cannot remember the exact lengths], allowing us to hold the contract to +450 instead of +480. Actually, the score was +420 for them because of an eight-ever-nine-never violation, perhaps done because of a fear that the cues had resulted in an unfavorable lead.
Now, I found this somewhat humorous, as it had been quite a while since any cuebidding sequence had a noticed detriment for me personally. The poor opponents!
I also recognized that my sequence would not have been entirely the same, as I would have opted to not raise diamonds (with xxx support and a minimum) and would not have made a serious slam move with Responder's hand. So, I technically may have avoided this problem. But, the reality exists that some sequences may result in a lead-direction that can be costly at MP scoring. As I hate MP anyway, my normal reaction is to find this to be a fortunately rare occurrence and to simply bid as I think I should anyway.
However, I do understand the concern. One possible tweak I considered at the time was to switch the meanings of 2NT and 3NT for matchpoints, and then making 2NT frivolous instead of serious. I don't think that this is ideal, but it might be a consideration at MP.
Imagine a sequence like 1♠-P-2♣-P-2♥-P-2♠. If Opener now bids 2NT, this could be a "frivolous" 2NT, rendering all other cuebids serious. (Picture Jumps remaining the same.) After a frivolous 2NT, Responder could sign off, or he could cuebid anyway with a hand that has slam prospects opposite a frivolous holding.
In either event, three of the major would still be a trump cue (two of the top three honors), bypassing of which would limit the major honor contribution. Also, 3NT would then be another "trump cue," showing extra trump above that already promised, or the the third trump honor, or two trump honors if partner has denied two, bypassing of which denies the same.
A direct 2NT-P-3NT sequence would seem to be a suggestion of 3NT as a MP contract.
The full permutations resulting from this MP tweak I have not worked out, nor will I because of my strong dislike of system impurity to cater to MP analysis and playing the (idiot?) field. Even if I were to try, my biases are too ingrained to allow me to do this effectively, I am sure. For anyone who likes this or a similar idea, please feel free to share your thoughts in the comments section.