How about % for jumping between #+BEGIN_<block> and #+END_<block>?

[Kazark]

Relevant.

The jump function is probably even something I could figure out how to implement if I did it raw; however I suspect that % is already bound in Evil and so I would need to rather define some kind of text object or something---comments appreciated.

[dalanicolai]

Are you asking, for opinions about this jump functionality? Or about information how to use text object commands with evil mode?

For the latter you can find evil interactive codes here
or in evil-types.el (in that file look for evil-define-interactive-code).

Also, I did not read this, but it might be helpful (e.g. I see it mentions org-elements which might provide your "text-objects")