Email + Emacs/Vim Keybindings + Latex = Does not exist?

Hi, I am looking email client (or web app) that supports the following two features:

1. Emacs/Vim keybindings
2. Latex support

As far as I can tell, this does not exist. I tried a few alternatives listed below, but they don't work all that well. Also, yes I know that I could use an email client directly in emacs (Mu4e, notmuch). However, this solution has issues with html emails, and seems like overkill for such a limited set of features...

Latex support

MarkDownHere (https://markdown-here.com/) + Email Webapp

This combination works pretty well, but the Latex rendering is kind of low resolution sometimes.

Emacs/Vim Bindings

Amazingly I could not find a single solution that really seems to nail these keybindings.

One attempt at a solution is to enable the keybidings in the browser and then use an email webapp. The following works for Firefox:

https://askubuntu.com/questions/245746/emacs-like-keybindings-system-wide

But this solution is not super compatible with email webapps. For exampl, Ctrl-b enables bold on the email webapp instead of shifting the cursor back. This solution also only works for a limited set of keybidings, i.e. no kill/yank combo in emacs.

Another possible solution is to use something like GhostText (https://github.com/fregante/GhostText) in the browser. However, this solution is unworkable because when you open up an email, all the nasty html shows up in the external editor.