I don't know how it would be beneficial. Keep in mind that these are book readers, and I really doubt that LineageOS will be well optimized for these E-INK screen devices. I find it more interesting if it were possible to boot a Linux ARM operation system
But if someone uses book readers for their banking, fine. I would just like to know how many and what applications are not available for Android 11 that it is so necessary to leave the entire Onyx ecosystem for these apps (and lose all benefits and applications, after switching to another Android it will be nothing more than looking for alternatives to the original applications and search, not to mention the overall stability of the OS.