The boards while on thr treadmill ate not cooperating today
As for the metal straws, I think you should be able to find one with a case/bag etc. Have a friend that has one and it lives in a drawstring baggy that is straw size.
Also they have brushes for cleaning straws. I have 2 sizes, one for my gym water bottle that's bigger and a smaller one for my tumbler straws.
I'm sure it wouldn't be a problem but do think about what you're drinking through a metal straw. While it wouldn't be terrible not sure I'd want to drink a frozen drink through one.