rcchris,
May I ask why you want to soft mount your OS160? I think the only times a soft mount is necessary are:

1. The fuse is fiberglass and very rigid or light
2. The fuse is extremely lightly built and needs the protection
3. You're running a strong four stroke with very violent power pulses, and one of the two above plays a role.

The H9 Edge540 is a wooden structure is quite sturdy too. I can't see an OS160 shaking anything apart on that plane, and a soft mount may even rob you of some top end power.

Just my humbe input.

DKjens