Turn on Summary Disk Usage for Existing Plan

I currently have a plan that did not have Summary Disk Usage enabled.

If I were to enable it now, are there any unforeseen after effects that I should be aware of? Such as data, mail, or control panel settings losses?

Or would the smarter option be to create a whole new plan with Summary Disk Usage enabled and then slowly move my clients over one by one, after they have backed up all their data?

Thanks for any advice on this!

there should be no issue in turning on summary disk just watch their billing statements for any funny charges the first month.

thanks for info!