FTW! Good advice. That would give you a way to keep earning income on your products even if the name itself gets "complicated" by potential future legal action.
Any of us who have done a successful startup knows that the name itself is great for marketing, but as soon as it becomes a liability be prepared to sell it or abandon it, if necessary.
Word of warning: legal action is a major expense, once it gets its teeth into any company. Even Microsoft suffered tremendously because of it.
Litigation is the most expensive legal action for both sides. If you can meet a challenge with an amicable settlement you will have a much greater chance for survival long-term. i.e., be prepared to cease and desist on the narrow issue of the name. Try to contain the legal issue.
My advice (which is solely personal. I am not a lawyer) is to do all you can to anticipate legal challenges and have files ready to go when your attorneys might need them. Or, if the IRS requests documentation. They require full and complete business records. The standard is nebulous, except as regard financial transactions. Those are pretty clear. Full and complete is safest.
Documentation is like disclosure. Just like the old joke about voting in Chicage. "do it early and often" Not publicly, necessarily, of course.
Before you even start using a trademark owned by a large company, you need to prepare your eventual defense theory.
Look at the case of Mr. McDonald who was told he can't use that name. Even though it was his.
And make sure you have a good attorney involved from the get-go. Don't let him prevent you from doing things so much as allow him to be ready for any legal challenges.
My 2c worth. Good fortune, my friend!