It has been a long time since anyone really seems to have considered a complete revamp of the basic building blocks for responding to 1NT. In thinking through some ideas, the area of 1NT responses popped up.
Is there a possible alternative core to potentially replace Stayman and Jacoby Transfers? How about something like this:
2D as Stayman, with invitational+ values. Opener bids 2S with four spades, 2H with neither major, 2NT with four hearts and a minimum, 3C with both majors (re-transfers), 3H or 3S with four and a maximum, 3D with neither but a maximum.
2C as one or both majors. Opener assumes 5-5 and bids 2D with spade preference, 2H with heart preference (2S for 22 majors). If Responder has both weak, he places contract. With just one weak, he bids it. With both invitational, raise preference. With just one but Opener preferenced, raise that. With just wrong one and six, jumps. With just wrong one and 5, notrumps.
2H as one or both minors invitational+. Opener picks minor preference to decline invites by bidding 3C or 2NT for diamonds, after which Responder places contract or can bid 3M as stiff from 5-5 and GF. If Opener would accept some invites, bids 2S, after which Responder bids 2NT minors, bids minor, or bids 3M shortness GF.
2S as one or both minors weak, or 3-1/1-3 majors GF. Opener shows minor preference, after which Responder places weak contract or bids stiff major if GF.
This is just a rough draft brainstorm. Much more would need to be filled in, of course, like perhaps Puppet 3C.