5-5 majors over 1NT

Last time I discussed using jumps to 3H and 3S over 1NT as one-suited slam tries, which allows for cue-bidding below game level. Many players use those jumps for 5-5 major hands, 3H = invite, 3S = game force. I think that treatment is inefficient, wasteful of useful bids, and completely unnecessary:

With 5-5 weak, transfer to the better major and pass; or use Stayman-then-2H as weak with both majors.

With 5-5 invitational, transfer to hearts, then bid 2S. A Stayman or transfer bid followed by a new suit at the two level has always been invitational; why leap to the three level? With 4-5 majors, start with Stayman. However, if you've agreed 1NT-2C-2D-2H is weak with both majors, 1NT-2D-2H-2S may be 4-5 or 5-5 invitational. Using the jump for the 5-5 hand does clarify things, but at the expense of forcing our side to the three level. And these days it's not uncommon for opener to have Kx Qx KJxxx AQxx for his 1NT opening, so the 3H puts us at the three level with no fit and not enough points for 3NT. Ugh.

With 5-5 game forcing, 1NT-2H-2S-3H has always shown this shape and strength; again, with 5-4 majors, you would start with Stayman, then jump in spades if opener replies 2D (or jump in the shorter major if playing Smolen.) The transfer-then-3H sequence gives opener room to confirm spade support (3S) or cue-bid in support of hearts (4C or 4D.) The 5-5 jump makes it impossible for opener to both cue-bid and specify what's trumps, which in turn makes it impossible for either player to cue-bid a major.

Giving up the useful 3H and 3S bids for an inferior, unnecessary treatment is worse than useless. Some experts assign special, artificial meanings to the transfer-then-other major sequences, but I've never seen one I thought was worth the memory load.

Note: novice players often treat 1NT-2H-2S-3H or 4H as "oops, I forgot we were playing transfers." This is illegal, of course, but since no advantage is gained and the bid usually puts them at a higher level and playing the contract from the wrong side, experienced opponents can generally content themselves with a mild chuckle and not make a fuss about it.