There is so much mis/dis information out there on the oil types and systems. Most of it propaganda from the oil makers themselves. It's actually HARD to find a true independent lab test (one that wasn't requested by someone with a stake in the game or a lab with a stake in the game) of oils and claims.
I only know what I've experienced in my own equipment and that's pretty much all I know about them. I have verification of the experience from other owners of similar equipment so I feel confident in what I do as working okay for what I have.
Oddly, those experiences run counter to and in line with some statements already made in this thread and I have no desire to indulge in oil religious discussions. So, I will not go into detail. I will take the wimpy way out:
Change your oil with the factory specified oils at the factory specified intervals and all warranties will remain in place and functioning to protect you. If you choose to deviate from those specifications attempting to save money (one way or the other) you are an adult and are free to do so. We all live with the consequences of our choices on a daily basis.
As for me, my L3200 will be getting a 50hr change with Kubota fluids. I'll pay the outrageous prices just so I can prove to them, if anything goes wrong, that they are on the hook for everything. Once it's out of warranty, I'll switch to the stuff I know works on my other gear.