Advice needed for an umcoming small project...maybe.

[Ombligo]

To prevent the water pooling, leave a gap between the ramp and the door of 4-6 inches, then put a couple 1x(whatever depth) boards on edge leaving gaps for the water to run though. No more pooling.

[Forrest]

Filling a 1-2 inch gap wood is not a good idea. The wood will rot in 1-2 years, based on experience.

I found HD or Lowes sells 1 inch square, solid PVC molding that works great for this application.