i have a 12.9” iPad Pro. I use Split View whenever I can and usually have Facebook or Twitter as the “pinned” second app on the right hand side. I believe in iOS 10 if you had an app “pinned” as your second app and then switched to another first app the second app would stay there so long as the first app supported Split View. Now with iOS 11 because these parings are preserved and it doesn’t appear you can have a many-to-one paring if you switch to another app without dragging and dropping it on to the first app the second “pinned” app goes away and you have to re-pair it. That’s kind of a pain because often times it’s quicker to double click the home button and select an app from multitasking than to drag and drop it from the dock. And it’s certainly quicker for apps that aren’t in the dock or are in folders in the dock. I wish there was way to “pin” a second app and treat it like a persistent sidebar or allow many-to-one app parings so long as both apps support Split View. Oh and I wish Apple would require all iPad apps to support Split View. And while they’re at it force all video apps to support PIP (yes I’m looking at you YouTube). Also Apple needs to make it easier to drag and drop from apps within folders in the dock and ones not on the dock. Starting to drag an app and then double clicking the home button to get multitasking is clunky.