IMHO Id steer away from tuning boxes, and stick to a map. Any doubts about your warranty, then wait till it's up, but happy to talk through all options if you want to give me a call.
Just picking up the point in the above post. I have had numerous vehicles professionally remapped by the relevant reputable company with consistantly good results.
I did once try a tuning box and it did not last long and I have a number friends who have tried boxes over the years and all changed to a proper ecu remap..
This is just my view and my experience, I have no affiliation to any tuning company.