Situation resolved by phoning kia customer service
Thank you for the adviceI agree - a temporary repair pending proper KIA dealer intervention is entirely defensible expedient action. Make sure the dealer understands that this has been done only recently to allow the car to be used and it is kinder to the engine than to leave it with a faulty EGR.
There might be other reasons why a warranty claim could be rejected (and which would anyway apply even if the car was immediately seen by the dealer) but I think you have a robust defence against the blanking being held to invalidate a claim. Also ask them to return the cap to you so you can give it back to the garage which fitted it.
A very fair outcome given the special circumstances.Good afternoon
We've left a voicemail for you Tredegarjack but if anyone else is curious, we've confirmed our dealer can accept the car with a blanked off EGR and will test the valve for manufacturing defects as usual.