The way I understand it, and I may be incorrect, the step is like the main gear. Too far back and the nose acts heavy where it takes a lot of elevator to get off the water, just like with a land plane that is really heavy on the nose gear, it takes a lot of up elevator to take off.

That being said, I have a Fazer on floats and originally the step was 3 inches or so behind the CG. It took off fine, but I was using a Tower .46 and had plenty of power and I also had 3D control throws. I would hold full up elevator and give full power and it jumped on the step. If I tried to stay down too long it would skip so now I take off quickly.

Now, I'm running a Saito .72 since I added dual water rudders and this moved the CG back more than I thought so I went to a slightly heavier engine. It still jumps off the water quickly.

I don't know how you are going to nose over if you are "flying" the plane on the water. I always (and was told to) hold full up elevator and add power. When the plane rides up on the step, I release about half the up and "fly" it on the water. It's not much longer after that the plane wants to lift off. Even with a scale plane, you have plenty of lift and some nice floats. I would give it a try.