Did a search for Owen’s a3 but didn’t find anything so hopefully not a common question… I’ve had a few OTB games trying out this opening for Black, but my opponent is quite coy and always wants to play a3 after I pin the knight with Bb4 (seems a common theme regardless of opening)… and they also put their e pawn on e6, defending e4 so negating a good portion of the e4 threats from the fianchetto’d bishop.

1. e4 b6 2. Nc3 Bb7 3. Nf3 e6 4. d3 Bb4 5. a3

I’ve moved the bishop back a couple of times to e7 (as d6 didn’t feel good blocking the d pawn).

Would just trading off the knight and mess up Whites pawn structure be the better option?