Since the export settings screenshot is a bit dated here is what I use for the latest version of Blender:
0.01 scale might seem odd but I have my units set to meters, and I scale my cars to their true size and this seems to be what works. Trying to export at 1.0 while following the old export settings initially had me confused as I couldn't see my car after importing in kseditor, turns out I was INSIDE the vehicles mesh because it was absolutely massive.
Here I check Apply Modifiers as it helps if you forget to apply any mirroring or subdivision modifiers. You can likely disable Bake Animation.
For the dummies I personally use the Arrows dummy in Blender and give it a 90d rotation on the X and 180d rotation on the Z, this will give you Y-Up and Z-Forward
Something to note, it can be an absolute pain having to make adjustments to a dummy position after you have already positioned its children, a bit tedious but less painful way of adjusting its position without ruining all your work is to:
Select the dummy
SHIFT+G > Children
CTRL+G > Create Collection (Name it)
ALT+P > Clear Parent
Move the dummy now as you please, then:
Select an object in the new collection
SHIFT+G > Collection
Hold SHIFT, select the dummy
CTRL+P > Object (Keep Transform)
All done, dummy has been moved, nothing got knocked out of position.