asdfghjkl: Thanks for the compliment. You have fine middos like Aharon, because your comments, on all the Divrei Torah, probably keep this thing going.
Pashuteh Yid: great pshat!
I will add to it. Now that we have the Rashba’s teretz for the issur of ba’al tigra, why is the other heter used for the mitzva of blowing shofar, namely, that the chachamin are oker bshev v’al ta’aseh. Lichaora, you can only use the extra streangth of takanos chazal in regard to ba’al tigra becacause it is kollel all the mitzvos and chazal similarly make takanos for all the mitzvos. But on each particular mitzvah, you must use the stam heter of shev va’l ta’aseh.