I'm not sure where the question about GF Stayman comes from with the DONT interference, but with a pass, I agree with everyone else - it's an invite. Perhaps it's GF if we catch a major fit, not sure.
If you play double of 2
♦ as cards, or specifically as takeout, then as discussed you should know how high that forces you (as "cards", I would suggest it's a different place than "takeout", unless you're not going to takeout on "pure shape" to push the preempt).
Once you know that, then you get to decide what the double means. For me, in both cases I would take it as "what about 2
♥x, pd?", with if takeout, "my hand's not great, 200 beats partscores" and if cards, "I've got some hearts, if you have some hearts, this might be better than anything else". But I would be almost certain that pass was forcing, so I get to be "pessimistic" (more interested in defending than pass".
But IIRC the XXX philosophy, "first double is cards, second double is takeout, third double is penalty". Equally playable.
And yet again, you want to have an agreement about double after pass:
My guess would be, if takeout, "more takeout (say
♥Hxx), but if you have some hearts..."; if cards, "takeout" (but again, passable).
I will admit that I don't care what the double means with the hand you give in the OP. I'm passing. They've pulled from what looked like their fit into a Moysian, we have 24ish points and bad breaks everywhere, I'm not worried about losing to 600 or 620. Yes, I see the hand; I'm - surprised (shouldn't 2
♥ be P/C?). Still taking my 500, and feeling a bit unlucky it isn't 8.
The weak NT (any weak NT) is a double-edged sword that requires rethinking from the ACBL norm from both sides. Yes, you get an advantage from the opponents not being used to it and not understanding where their goal lies; but they will do it anyway - and there's no worse feeling as a weak NTer than to let 800 (or 200 into nothing, or 300 into NV game (losing to all the +110s, too!)) get away, especially because you also frequently go down if you end up declaring. And since opponents come in on trash, despite all the lessons, you get more opportunities for it than the "the weak NT goes for numbers" opponents get, at least outside of the full flighted A games.
Long live the Republic-k. -- Major General J. Golding Frederick (tSCoSI)