My ancient Mk.2 Superb 2.0 TSi was purchased when it was 9 months old, ( Feb. 2013) & was treated to an AMD Stage 1 map about 6 weeks later. I still own the car, it gets more use than our Golfs & it hasn't shown any sign of distress yet. AMD set the car up to run on 95 octane petrol, ('cos that's all that was available in this town), the before figures were
215 PS & 291 Nm, after the map it made 252 PS & 361 Nm. A decent & noticeable improvement, but probably not enough to to damage the engine & transmission.
FWIW, we've also had AMD map 2 x VW EOS's & 2 x Octy vRS's. again all of them optimised to cope with 95 octane, no problems with any of them.
The (very conservative) nominal 200 PS TSi's that Skoda used in the vRS & Superb were (& still are) very engines to live with, if they weren't my Superb wouldn't still be my daily driver.............
(The last EOS was sold to enable the purchase of a Golf R hatch (mine) & the last vRS was swapped for a Golf R Wagon (her's), neither of them tweaked at all, both are nice cars but when driven on the same roads / speeds. they burn more fuel the the Superb, Not a problem given our low mileages but quite amusing.