Open K8o from SB, mix flop, then check turn on the third diamond; once we bet and face a shove, the price and our draw make calling off mandatory.
Flop T64dd gives us K-high with a backdoor flush draw on a semi-wet board. Solver leans heavily toward checking here, with some small bets mixed in. Our 2.3BB c-bet is a bit on the large side for this combo; a smaller stab or check would be slightly higher EV.
Note: C-bet sizing is a bit too big for a marginal high-card hand with backdoor flush potential; prefer a smaller bet or check.
Turn 3d brings the third diamond and completes the front-door flush draw. With SPR ≈1.6 and our hand now a strong diamond draw, strategy leans toward checking and letting BB act. Once we bet and face a shove, we’re getting about 3.3:1 and need ~23% equity. Kd8h has 9 clean outs (Kd, 8d, 9d, 5d, 2d) plus some thin equity from K-high, so calling off is correct.