I know this has been available for a while, but I was just using it and though I should shout about how fantastic and useful it is.
In the past when completing reviews, I would either have to have my weekly review checklist on the iPhone, or jump backwards and forwards on the iPad between my Weekly review project and the things I need to look at in OF. I would often get distracted into other things.
On the iPad 12.9” I can have a 1/4 version on the right with my Weekly Review Project open, and work in the left hand view 3/4 reviewing projects, processing my inbox and the like and I’ve always got the Weekly Review project on the right to remind me to keep focused.
I use the slideover panel to keep a Numbers document with my GTD checklists. Numbers is free and available for any iOS device. I can slide it out of the way when I don’t need it temporarily and slide it back out when I need it. Numbers allows me to create a Numbers document with multiple sheets. I have sheets for the daily review, weekly review, and monthly review from GTD. I took this and can customize it to fit my personal workflow. Everyone’s checklist is different and it would be easy to rearrange to fit your needs.
I don’t do the split screen like you because my workflows may jump from OmniFocus to other apps. For example, I’ll switch to Mail.app to clear out my inbox. Then I’ll go to Fantastical to get the next 4 weeks view. Next up is the Files app and Dropbox to check for pending downloads to handle/process. Then I’ll return back to OmniFocus and process further.