having had the chance to test on a friends Aura HD 3.18.0 in English that is direct from Kobo I can say that my delays, offsets and patterns worked perfectly every time.
however, changing the affiliate on mine to Kobo did, as I mentioned, somehow stop the screensavers from working at all.
I didn't try setting his affiliate=Eason because I wasn't sure that the affiliate image would be built in and wouldn't cause some sort of boot issue due to a missing resource so I've no clue how that changes things.
I wasn't experimenting with any different delays yet today but I have noticed that the simpler the screensaver image the more likely it is that the affiliate image overwrites it (your default KittenTree2 image is always over written) whereas large 1.5-1.9MB images will always show if they are selected (eg.
this or
this) so I'm assuming that I have to adjust the delays further to account for the affiliate screensaver and the size of the file.
also, and annoyingly, on my friends the screensaver appears when it times out and sleeps/turns off so that's fine but on mine it hits 15 mins (how I noticed it), or the 1 min I was using to test, and it goes right to the Easons one without mine even flickering.
*Edit:* A bit of further testing shows that a
copy of the second image linked there with the colours reversed to be mostly white is also generally either fully or partially overwritten so it may be that it takes more time to parse/draw the image. Which doesn't explain why it works perfectly fine on his every time unless the affiliate screensavers are written using a similar method to yours.
*Edit 2:* I also noticed that when his times out the regular 'Sleeping' or 'Power Off' show up whereas on mine, when it automatically sleeps, it goes directly to the Easons screensaver without displaying a sleep message... Which I suppose neatly explains why the screensaver doesn't work in those cases.