With a 5% cap 4€ rake structure like here, the EV of the xback is 0.975€.
And if villain calls all-in you lose €1, but if he folds you win €1.95.
He would have to fold exactly 67% of the time for shove to be a better strategy than check but in our reality, I think that villain will call 98%+ of the time, we will lose 2bb EV and generously give €2 to Ipoker.