unicode-math-input.el VS ctrlf

unicode-math-input: Input method like the built-in TeX, but with complete coverage of Unicode math symbols.

isearch-mb: A subtle modification to isearch (C-s and friends) giving it a more “normal” feel by today's standards. Basically, allows you to edit the search string while searching. Similar to ctrlf, but less invasive of a change, and arguably more robust.

See if ctrlf is to your liking. It seems to have this feature, among others.

Consider using raxod502/ctrlf instead if you won't use anything else ivy/swiper offer.

Have a look at CTRLF. When you hit "C-s" for ctrlf-forward-default (i-search). Now type what you're searching for. Then you can do "M-s o". That will open a Occur buffer with the existing search input. Not sure that you can edit in that buffer tho.

CtrlF and Isearch MB also have this behavior.

CTRLF replacing packages such as Isearch

I viewed Prot's video back in January on Embark, Consult, and Orderless; I found them interesting, but not really fitting into my workflow and of course, not a reason to replace Swiper. But I was not thinking about how the packages were working--something you've looked into. Reading the Selectrum page about comparisons, I think I might like CtrlF a bit better than Swiper, though I've yet to try it.