Posted Today, 05:16
This is one of the problems I'm happy to no longer have to deal with, playing Maas 2NT. Bundling the limit raises with minimum GF hands allows for evaluating after we have a bit more information, systemically reduces information leakage, and lets me show support right away.
In more standard 2/1 structures the limit raise, especially the 3-card limit raise, is a problem hand. You can put it in 1NT, or reserve a bid for it at the 3-level, or adapt the structure a different way to cater to it. One of the questions I always ask in a pickup partnership is their raise structure of 1M, as all approaches come with some downsides and everybody seems to play their own flavour.
On this actual start, I don't like 1♥-1♠ with a heart fit at all. There are quite a few rebids for opener over which our support becomes ambiguous, such as 2♥, 2♠, 3♣, 3♦ and 3♥. Some of these also make our strength ambiguous. I think solutions and agreements exist for all of these auctions, but in my experience most partnerships haven't discussed e.g. 1♥-1♠; 2♠-3♥, let alone the nasty nuances of 1♥-1♠; 3♦-? (probably 3♥ ambiguous, then pull to 4♥?). By contrast the 1♥-1♠; 2m auctions are easier, though here too people play different styles and approaches. I think this is also in part why some people play Kaplan Inversion - the natural start to the auction is just not that pleasant.
If the opponents interfere everything changes, though on this start sometimes for the better. It's not very likely with our decently strong flat hand, but the possibly exists.
For all those reasons I would bid 2♣, forcing to game, intending to support hearts next round in a Maasless 2/1 system. This way I get very good chances of being able to show my support and hand type (balanced raise), at the cost of slightly overvalueing the hand.
And in the future I would aim to discuss the raise structure of the major suits with partner. In general I am not a fan of bundling fit hands with non-fit hands, and I believe in showing support early to let partner re-evaluate. In my current system delayed voluntary support is always a slam try, which I feel is an acceptable cost.