Oil yes , diffs and TC no.It's probably been asked already, but is there provision for oil changes on the custom off-road set?
I had ARB underbody protection on my DMax and it was a PITA to do maintenance so I ran some holes into it for the component drain plugs. A fumoto oil drain valve in place of the engine sump plug was also a good investment.
You could cut your own holes.
I have a drain valve on the tank of my old 911. Always ziptie the lever to prevent a rock or some malevolent numpty opening it!