corfu VS consult-flycheck

You could try corfu. It has auto-completion disabled by default and works most places with M-Tab. Or you could set a longish corfu-auto-delay (0.75s say), and let auto popup only when you stop to ponder a while.

Corfu supports this. Or at least it allows you to move completions to the mini buffer which I find quiet useful.

A substantial section of the community is using corfu instead of company, but I wouldn't say company is out of date by any means. In emacs 29 eglot will be a built in, which might act as a replacement for lsp-mode depending on what functionality you need.

Wow, interesting that my response is getting down voted. It seems not enough that I give away my work for free. Nevertheless I appreciate support from the community, as other Emacs package developers. The support is actually helpful. To clarify, publishing my configuration would translate into quite a bit of work, requiring separation of private and public bits.

I am currently using evil and corfu, but I want to configure such that pressing a single escape will invoke corfu-quit when its UI is active (because pressing "C-g" is harder).

A few days ago I found an unexplained slowness when using Corfu on Emacs 29 with pgtk. I stripped my configuration to basically just Corfu, and still had a noticeable delay. Maybe it is related to your problem. https://github.com/minad/corfu/issues/307

The most straight forward solution is probably the package company-math. (that's what I use but with corfu and cape)

See here: https://github.com/minad/corfu/issues/231

I've only been skeptical, I didn't reject the idea. If you read my very first comment in the thread were you suggested adding the package to ELPA, I wrote that I already had considered it. So I think nothing has really changed. I had to test first how the ELPA workflow works, which I did with my Vertico and Corfu packages. After that went positive, there was no strong argument to not make the move. Initially I was hesitant since ELPA requires the assignment, I didn't have it at that time and I wasn't yet sure about the direction Consult was taking. It could have been that Consult would have been much more of a kitchen sink with many contributors, accepting more controversial commands. But then I concluded that it is better to keep Consult somehow focused (it still is a kitchen sink!), and keep wider functionality in external packages to help with the modularity. This is mainly thanks to /u/purcell who convinced me to not throw everything together in a single consult.el file, when I added consult-flycheck, which lives now in its own repository outside ELPA.