Unless you specced DCC, there is definitely no stiffening of the suspension - that cannot happen without active dampers, and active dampers are not standard UK spec.
Me and the missus each have a V2 E-Boost. When you put it in
Cupra mode, you get the heavier steering, a sharper steering response and "B" mode type regen when you lift off the accelerator, even if you're in D mode, which I find highly annoying - leave me with the choice to put it in B mode if I want.
Having the car in
Cupra mode, with that enforced regen when you lift off makes it harder to drive smoothly, because the car's always looking to slow down when you're not pressing on - feels like driving with the handbrake on. If there's one thing I would want a software tweak on, it would be to remove the "B" mode effect on
Cupra, if you have "D" selected.
People have looked at part numbers between the motors on the ID3 on the VAG parts system (EKTA?) and seen a difference between the 150ps and 204ps units that suggests that they are physically different, rather than software being the only differentiator. I don't think anyone's done the same for the E-Boost unit to compare.
The difference between our old 204ps ID3 and Born e-Boost isn't startling, as you might expect, with only 27ps extra - the difference is like taking a Golf GTI sitting at 60mph and seeing the acceleration difference between putting your foot down in 4th and 5th. Noticeable, but won't knock your socks off.
I'm surprised that visually, the only differentiator for E-Boost is the satellite buttons on the steering wheel.
Given the expectation for these cars to remain connected for regular updates, getting your output increased on the sly may well end up being very visible to VAG, putting your warranty at risk.