A good idea to set ideal video to 480?

I’ve seen recommendations to change the ideal video constraint in config.js to 480 from 720. The default sets ideal at 720, max 720, min 240. I’d prefer 720, but 480 is ok if necessary.

Does jvb change the video on the fly? Is it smart enough to reduce resolution if needed? In other words, can I leave the ideal at 720 and let jvb reduce it if necessary?