Pal Anders Ullevalseter told me this summer that no stickers - regardless of adhesive - would stick to those nylon/plastic (whatever) front or rear tanks for a long time. They "sweat" fuel vapours and require constant attention even for his sponsor-stickers. No big deal, really.
Goes with the territory; these tanks are made for maximum capacity and a reasonable crash-tolerance in rally-conditions within a certain temperature-range. If you want permanent stickers, go elsewhere.
In my world this is only a small rally-character treat of this bike. If you see the preps for Dakar and other rallies, mechanics use heat-guns to make sponsor-stickers hang in there for a while. Given the crash-tolerance of these tanks, that's a small price to pay.
And plastic or nylon tanks - each have their own advantages and trade-offs.
These rally-bikes are by design demanding more attention and scrutineering.
That's cool enough in my book