My integrated weights interfere. Maybe it's the AquaLung design. If I have very much in the pockets, the weights won't slide all the way in and lock into place. The weights seem to occupy the same "space" but theres a nylon divider separating the cargo pocket from the weight pouch area. I'd never be able to fit a mask into a pocket with my weights in place. Even my AL Teknika is a low-profile mask but I can't zip the pocket closed with it in there with the weights in place.
I got my Shearwater on my wrist but my backup is the ScubaPro Matrix on the console. SMB and reel clipped to stainless loops on my weight belt. My tiny little Princeton Tech AA flashlight just manages to fit in the right pocket and allow it to zip closed. I keep the slate in the left pocket, and it's not thick enough to matter.
The whistle is clipped onto my SMB so it's not a storage factor.
I also have integrated weights and they do take room. How much weight are you taking.