[jpwgarrison]

It looks like keyboard shortcuts don't work here? I tried the new Thunderbird, but it looks like you (still) need an extension to change keyboard shortcuts and none of them work with v68 even if you don't mind third party extensions.

[longtom]

For anyone interested, I just put together a userscript with some rudimentary key assignments for the Basic HTML version of Gmail:

https://pastebin.com/raw/zyfHp5Vs