Zoom released new firmware for the H6 essential Looks like on 12 November that offers multitrack mode. This is very exciting! As it will allow us to overdub using the recorder. I installed the latest guide file for voice guidance and the new firmware, had speaking menus until I get into multitrack mode and now it just beeps. turning off the recorder and turning it back on leaves you in multitrack mode. The screen looks like from an AI view that it shows four tracks and a master mix track, but there is from what I can tell no way to get out of this mode yet, so please hold off on testing. I’m going to contact Zoom about this myself.
I will update this post when I find more information. Please feel free to share with other Zoom users, hopefully spreading the word that accessibility may break on the recorder 
Update:
I honestly did work on that for about 30 to 45 minutes before making this post. I definitely wasn’t trying to be excited. I will share this though, if you turn the recorder on and it’s in multitrack mode and it beeps at you and you press the enter button four times, you should get back to the regular mode. I’m gonna call it stereo mode. So I’m gonna say at this point that multitrack is not accessible with voice guidance. Just wanted to get you this update