"At the very least, you could see whether the candidate could learn a new notation, and that alone is a pretty valuable signal." I could see that as a benefit.

"At the very least, you could see whether the candidate could learn a new notation, and that alone is a pretty valuable signal." I could see that as a benefit. Much like how they would have to learn unusual requirements or API's on the job then solve problems with them. A notation like this and basic specs might be a useful filter.