Engine comparison is not valid. I'm sure it's slightly cooler fluid at the bottom, but I don't think it's a big deal. Windage isn't a problem, there's no where for the fluid to "slosh" around like an engine.

If the fluid level is full, I think it's good to go. I have deep pan on my 518 with no extension.
Only put 3-4K on it so far, we'll see how it goes.