I think the Split view is extremely handy for quickly peeking into different Records quickly and we use it quite a bit. However it is very irritating that whenever I click a record, The “List” scrolls up to the very top.
You basically scroll down to the the Records you want to look at, but as soon as you click one, it is being scrolled to the top. So every time i want to see the record above, I have to scroll back down and click that one. then when i want to see another one above that one - more scrolling again. And at the same time you easily loose sight of what record you are looking at because the List keeps jumping around. Not very pleasant if you’re trying to work through a bunch of records.
This type view is used in just about every E-Mail Program and many others and I’ve never seen it behave like this anywhere.
It would be a small change but I think it would improve that whole view by a lot! Would love for it to be considered 
Also it would be awesome if you could use the Split view on a regular Page or within a Record Page - Though I’d guess that would be a bigger change.
Oh and currently if you use groups in the Split view, the Group Header is ignored so the currently selected record is cut off/ hidden under the Group Header.