That's good to know. The Mail app shortcut keys don't make a lick of sense, but I don't mind that as much as the inability to zoom in on images in a message. No pinch and zoom on an image is diabolical in the MacOS ecosystem. Do you miss anything about Mail now that you're Thunderbird full-time? Anything you prefer in Thunderbird over Mail?
100% multi-thread download and synch of folder contents, instantaneous display of messages, super-responsive.
I've tried a lot of clients on Windows and Linux and none of them get near the experience I had 20 years ago.