Defend pre, take the small flop stab with bottom pair, then mostly check the A turn and let BU drive the action.
On 5s‑6d‑7c rainbow, we flop bottom pair plus a gutshot, which is a nice but fragile hand. BU’s range is strong, but a small 2BB lead into 4.5BB works well as a mix of value and protection—picking up folds from overcards and random floats while not committing too much.
The Ah on the turn is a big card for BU’s range—lots of Ax and strong draws now show up, while our hand is still just bottom pair plus a gutshot. With SPR around 4.2 and a medium pot, we should mostly check and let BU continue with their Ax and bluffs; firing again with this hand is too ambitious and tends to isolate us against better one‑pair hands and strong draws.