I did a little research regarding ECU remaps and warranty.
The first thing that needs to be clarified is that the warranty is given by the factory(i.e. Seat) and NOT the whatever dealer. That means whatever remap you perform you warranty is void.
There are other ways to keep your warranty. This can be achieved in two ways.
1) All dealers have private insurances. They can exploit that and still cover your damage even if it is due to remap. This apply only if you do it on the dealer and he/she agrees with the above plan.
2)This happens in my country which laws are made to be broken dunno if UK garages are willing/can do this. Garages ussually have some connection in dealers/importers, for a few $$$ in the right pockets, they can cover your damage and blame it on something else, this is a bit complicated because the Seat factory might ask for the ECU to be sent over there for examination, so its a bit relative what will happen.
The conclusion is that you will NEVER be coverd by Seat factory if you flash your ECU, there are ways tho to do it , as someone from the tuning scene told me tuning is for people with nerves of steel.
All sort of stuff can happen maybe due to remap or maybe it was ment to happen. Everybody must take the decision for them selves, and be willing to pay the consequenses if they ever arise.
To answer your initial question a decent custom stage 1 with good peripherals is safe for this car. Revo is also a good choise, but bare in mind it plays a great role how you drive your car and not so much the remap.
