Being Emacs, it's just a matter of customization. In your example, it would probably be enough to apply advice to one of the Ivy functions to split the window appropriately when a candidate is selected. A few lines of code.
> being emacs ... customization ... a few lines of code
I see where you are heading and I am not following you in this rabbit hole ;)
I came to use emacs for org mode, when what I really wanted was to use org mode in vim. We can’t have All the nice things, so it’s okay, I’ll live with that. I actually found out I could use emacs as a "org mode beautifier" in neoformat.vim; it is slow, but it can tangle the org file and output back to vim. Good enough.
I have come to split first and search second.
It’s all about personal preferences.