quelpa VS icomplete-vertical

check out quelpa, it makes it easy.

There is another alternative if you want to install package that's not on MELPA or ELPA, it's https://github.com/quelpa/quelpa. It's using package.el so fully compatible with your current 200 packages, just only use it for package you want. Not only that, it supports to install packages from multiple SVC, not only git like straight.el

or with quelpa:

You can display icomplete/fido vertically if you like that better with (setq icomplete-separator "\n") or with https://github.com/oantolin/icomplete-vertical

I don't use icomplete nor vertico most of the time, but I am very familiar with them. I've tried lots of completion UIs: default completion, ido (with ido-completing-read to get it everywhere), icomplete, vertico, selectrum, helm, ivy; and I've written several myself: icomplete-vertical, live-completions, grille, embark-collections-completions.

Helm commands only work in Helm. Ivy and Counsel commands only work in Ivy. Consult commands work in Selectrum, Vertico, Icomplete Vertical, and maybe some other interfaces. That's all I meant. Of course, that only matters if you don't wish to use Helm or Ivy.

Consult supports asynchronous candidate sources now! This allows to implement grep and find commands which update the candidate lists while you type. Consult is made to work well with the default completion system, Selectrum and Icomplete-vertical.