Google makes Gmail work with iPad multitasking0
You can indeed make use of Apple's so-called Split View feature and switch between Gmail and other apps, but the functionality doesn't work flawlessly all the time. Although it took Google several years to implement multitasking within Gmail, the option is finally here.
Google announced today that all Gmail accounts – G Suite and personal, can now make use of the multitasking feature with Gmail and other iOS applications. It works the same way as Split View, but it's better to implement and specifically designed for Gmail.
You'll have to turn on Multitasking on your iPad before you'll be able to use the new feature by heading to Settings app / Home Screen & Dock / Multitasking. From there, make sure to enable the “Allow Multiple Apps” option to be able to switch between apps.
After you've enabled Multitasking, you can enter split view when in Gmail by swiping up from the bottom of the screen to open the dock. Then, touch and hold the app you wish to open and drag it to the left of the right edge of the screen.