[olog-hai]

> Being able to browse email in the background while composing email is a huge win

It was possible to do this before the changes rolled out. Shift-compose opened it (still does) in a new window, and you could work with it and your mailbox side-by-side.

[dasil003]

Not in reply it wasn't.

[ciniglio]

Shift+R could do it (Shift+a for reply all)

https://support.google.com/mail/answer/6594?hl=en

[dasil003]

I remember trying and being unable to do it. You may be right but current documentation doesn't really prove it.