> They aren't dogfooding this

The year is 2026 and ThunderBird still insists what a single SMTP outbound server for all your accounts is totes fine. Sure, if you insist it would configure a separate one, but all SMTP configuration is under a separate "Ougoing Server (SMTP)" option and not under the account.

> They need to seek out the power users

They are in a fine and cozy place "giving value" and "providing the alternative to a corporate capture". They are not interested.