I'm having trouble imagining how if you move the floats forward so that the step is in the conventionally accepted location, the floats stick 3 1/2 inches in front of the prop, but the main gear is almost at the transom, and the front gear is behind the middle of the float.

The step is almost always at 50% of the length of the float. The Main gears are close to the balance point so they go close to the step. If you have a taildragger, then the mains attach a little in front of the step and the rear struts attach about 5" behind the step.
If you have a trike gear trainer, the mains attach almost exactly where the step is, and you can make a t-shaped strut that attaches where the nose gear normally attaches. But the float should only stick forward of the prop by 20-30% of the prop diameter.

So having both struts attached behind the step and a big chunk of the float in front of the prop just sounds like there is a fundamental misunderstanding going on.

Maybe I'm just missing something.