A bit related - do you ever go from PR comments to DMs? Sometimes when discussions are needed, it feels much easier to just chat 1 on 1. Especially if it's a small team and everyone's close. Though that prevents others from experiencing the "interaction".
What about clarifications? In a sense when you're not sure if this is good code, and would need to get more details. I sometimes just ask directly ("Why is this there?"/"What does this do?"), but other times I just don't bother and let others review.
> Once we’re happy with the performance and stability of Vulkan across devices we will remove the OpenGL implementation.
So not for long.