I have 11.5 in 2024 bc3, 2025 grape 5 and wc4, 2026 infrared 6, and now these 15s. They all feel a little looser than 11.5 used to but still comfortable - definitely couldn't size down.
What I mean by that is I feel like 2018 bc3/2024 bc3 fit differently (less padding in 2024, slightly looser)...