[tbrownaw]

How would this interact with existing rules around exempt / non-exempt (roughly, salaried vs hourly) employees?

I would think it would already be expensive to make someone paid by the hour do extra work stuff during time they're not already being paid for.

[tptacek]

It doesn't. As drafted it applies to exempt employees. (It's just a proposed bill; it's unlikely to happen and if it picked up any steam presumably it would be drafted more carefully.)