Nope, they are only needed for custom kernel builds. For me it was a completely different thing.

To create the bootmenu mer.item file, I used Far Manager with WinSCP plugin.
I noticed strange music note-like symbols in the "Booting from..." line.

I deleted the file, sshed into the device using putty, run vi (the ugliest editor I've ever seen - why command mode, why not use ctrl-command combinations which are industry standart?)
and copy-pasted the insides for the file into the putty session, and saved the file as mer.item in VI.

And it finally started!! Probably a codepage issue. I assume the same results could be achived by gui versions of text editors inside Ubuntu or whatever.

Anyway, Mer started. Finally.
Now I'm stuck and the "Please be sure your username..." stage. It keeps prompting for a username regardless of what I type.

UPD: got it... used "a" for full name and "b" for username... You've got to have no cursor blinking in the enter area or something like that. Anyway, after giving a name to the device (name-tablet), it's just black screen and nothing more. If you have the virtual keyboard onscreen, it hangs...on reboot, setup is all over again