Different notification icons on per account basis

Expected behavior

It would be nice if it would be possible to configure accounts to have different icons in the notifications

Actual behavior

All notifications from all accounts have same icon.

Steps to reproduce

Motivation: currently I'm using k9mail for my "work email" (because it handles imap better and I had some weird issue ages ago with gmail handling) and I'm using +typeApp for my "personal" emails (on gmail). The other day I was annoyed with the +type app not respecting synchronisation (and their response that "we know better and we will ignore system synchronisation setting") that I decided to switch to k9mail all my accounts and the experience was very positive (archiving works, yay). However I've noticed that I grew accustomed to being able to differentiate with a quick glance to which account email from particular notification arrived (I'm usually on silent mode so different sounds won't work).

I'm not sure if it's technically possible, but would be great!

Environment

K-9 Mail version: 5.203

Android version: 6.0.1

Account type (IMAP, POP3, WebDAV/Exchange): n/a

No file, test, or entry point is named. Start by locating the Android notification and account-configuration code, then determine whether notification icons can be selected per account. Done means accounts can use different configured icons and notifications visibly preserve that distinction.