I'm not the one doing the review, I just noticed a typo.

Do you still have to unwrap() manually in case of backend API mismatch?

Do you still have to unwrap() manually in case of backend API mismatch?

Yes all apis return options.

I'd rather it unwrap in wgpu, personally. I can't imagine why you would want it to be optional.

Users are likely going to perform a backend check higher-up, and switch between e.g. dlss_vk and dlss_dx.

Very strongly in favor of keeping options instead of wgpu-internal unwrap!
The check has to be done somewhere and passing the option on is preferable to an internal unwrap. Sure often there's a higher level check first. But there's also other situations where I may do a speculative as_hal and then don't act on it if it didn't work out.

And either way we need less unwraps in wgpu when we can avoid it! I never ever want to leave my users with an application crashing inside of wgpu because I didn't real all the details of a docstring warning about correct use.