Allot, almost all, except for the part on the other side. It also depend if you have it on side stand or midstand. So best use both in the order as shown (as the first one is bigger hole, so it's fast ;-)).
Why oil sensor is ON when there is 4 liters of oil inside the engine? I have this situation several times while morning start, oil sensor RED, then I checked the dipstick and there was no oil level... all dry. After that I started engine second time and everything became OK, level oil OK, very strange.
According to the service manual it should be filled with 3l and rev it five or six time. But this is what the manual is recommending, probably to move a little bit the oil true the circuit, to fill it easier. Probably filling it with 3.7 it is also fine. "The engine should be filled with oil in two steps. First fill the engine with 3.0 liters of oil. Then start the engine and race it five or six time. Stop the engine and fill it with oil to the specified level."
The tdm 900 has a dry sump oil system. Never had a bike like that. Maybe that's the reason there's no problem running the engine with way too little oil
3Liter + is ok; However remember some parts of the engine and filter are "empty" so you risk overfilling and spilling. You idle or ref a few times, to led the oil pump fill the filter and all airpockets, before final fill.