It works! Now what to do with it...
Ok, I can report that the plugin works as advertised on the Glo, with firmware 2.1.5. The only unusual thing is that the clock still appears over the brightness slider when it's activated in the bottom menu bar. I may be confused but was there not also an option for having a dropdown menu for Shelves, replacing the previous 'Reading' and 'Discover' menus, on the home screen? I've just got blank space around my book covers and the Library / Shelves / Tools menus.
So ikarus9999, thanks for the excellent work on this - it seems to offer the possibility of making the device a lot more customisable. How did you work it out? Do Kobo have any docs about the plugin API?
I would really like to know if it's possible to get a true fullscreen mode working through this, using all the screen space for text. I can't believe how much of the screen is not used - it varies from page to page but sometimes it seems like an extra few lines are left empty, far above the page numbers, for some unknown layout reason.
The other big missing feature that I wonder if the plugin can address is the ability to do some kind of 'custom sync', i.e. have the device check a specific server for new books to automatically download - potentially a Dropbox folder, your own computer running Calibre's web server, or any other server space. This would also open up the option of sending articles to the device via browser extensions, something I found very useful to do with the Kindle and which is easy because of the email address they provide to do this.
Also wondering if the plugin allows access to interpreting touchpad gestures? Could anything closer to multi-touch gestures work? Might be nice to have gestures for jumping forward/back by chapters, rather than the cumbersome menu-based default on the Touch/Glo.
Anyway, thanks again, here's to fully open and hackable reading devices. I hope Kobo supports this stuff, as it seems it could give them an edge over the very locked-down Kindle...