It's fine, especially just for a bit too much wax on a toe. He doesn't need stripping right down to the grain. Why use something harsher if it isn't necessary?
Renovateur is allegedly a conditioner, but it is honestly more of a polish. Lexol is a water based emulsion with no wax in it. It is meant to penetrate into leather and stay there. Renovateur is a polish with a bit of oil content. I haven't had "luck" with it in the conditioning department.
You need to plump up the leather fibers so water and vinegar is meant to due that while maintaining a leather safe pH. Leather shrinks because of alkaline overexposure, the vinegar will keep this from happening. After doing this, I'd recommend a conditioner like Lexol or Bick4.
Renomat is a stripper with acetone in it. It is not a necessary shoe care product unless you're experimenting or caking your shoes with so much polish that you need to strip it away.