Alex, good to hear you’re improving on those things. The mp only exercises are not easy but as you are seeing, they will help develop the embouchure.
As for the low notes, only more air will help get you there.
Reeds warp because they are made from natural cane, the tip is thin and so will naturally warp as it goes from being wet to dry.
You can prevent this by taking your reed off after playing and laying it down on a firm flat surface like a small mirror, but put pressure on it like with an elastic band to firmly push the tip against the surface. I think they sell things that do this.
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