Some people like a mirror shine on their shoes. Apparently maintaining this involves applying many layers of wax. Keeping the shine apparently requires frequent repetition. This would lead to accumulation of wax. The wax may attract dust and dirt. So the shoes could become caked with dirt-impregnated wax. That might require regular stripping of the wax with something like Renomat. Since this removes fat, something like Renovateur might be needed to replace the oils removed by the Renomat. At this point the leather could be oiled, but still dehydrated. Repeated cycles of stripping out fat and replacing it, and not replacing the water, might be harmful.
Since I don't want a shine, I use little to no wax, and hence have no need to remove it. But my approach will never produce that mirror shine so many desire.
If you apply lots of wax, you may find yourself obligated to do some variation of periodic stripping and re-oiling. I'm no expert, but this does not sound like it would be good for leather.
For someone who lives in NYC and spends a lot on shoes, it may make sense to just turn maintenance over to B Nelson. The cost may be trivial compared to losing expensive shoes to cracking after a few years. And you would be sure the job would be done right.
I am too cheap to go that route, and I like to tinker. Hence all the study of leather chemistry.
Why should a oil replenish the leather if added to the surface and not the water? Especially if you have striped your shoe from wax and oils with renomat?
Renovateur is a water based product, it is an emulsion of oil and water!
Therefore it will refinish the water as well as the oils in the leather!