Just for Australians, without wanting to throw a further spanner in the works, technically (from a roadworthy inspection perspective) you can't increase the power of a stock vehicle by more than 20% without requiring an engineering certification from a qualified certifier. I'm just the messenger but back when I had a Polo in 2012 I never went ahead with a third party tune as it exceeded the limit. But there was one tuner aware of the limitations and I recall they deliberately increased the power by 19% but gave you a very nice fat midrange.
Perhaps this is something tuning providers could bear in mind. There is no rule about torque increases - just power increases

Nothing top stop you having a tuning option that gives you a nice torque increase in the low to midrange but then tapers it off so as to not add more than 19% additional maximum power output.
And yes, I know it is a stupid rule but on the other hand I guess you have to draw a line in the sand somewhere. You only have to compare a turbo car on a stinking hot and dry day in the middle of summer at altitude with one in very cold humid weather near sea level and you already have a substantial variation.
I am only mentioning this as it has nothing whatsoever to do with warranties but could potentially be an insurance snag because insurers require that your car is technically able to pass a roadworthy.
Other countries would have other laws so I only know the situation in Australia. In the case of the Picanto GT, that effectively limits any modification to producing around 90 Kw or 120 hp maximum.