The Schuhler Gambit is a line in the Sokolsky Opening.
[FEN ""] 1. b4 c6 2.Bb2 a5 3.b5 cxb5 4.e4
White gives away their b-pawn here. Stockfish claims this actually gives a small advantage to White, (although I analyzed only to depth 25) while bxa5 gives a small advantage to Black.
Why is it good and what is White's plan?