No technical reasoning, anything more than 5K+ KMs should be fine with remapping. Warranty is one thing, but personally, I feel let car be in OE condition for few years. Even light upgrade (if wire cutting is required) I suggest to get it done after warranty period. In my view, even OE tuned car is not that bad, once you adjust to gear shift at proper rpm, as per your drive, it works well. But after remapping, your life changes .