But if they had reason to suspect a remap had been done, say a post on an internet forum mentioning it for example, I doubt it would be much effort for them to "consult" someone who had the software and could tell...
If you're not aware, and it can't be shown that you might be aware, then it shouldn't invalidate your policy should it not be declared - it's similar to proving intent in a criminal case though, there's not definitive way of proving you were (or weren't) aware.