Is there any benefit to reinforcing Iron Scaffolding with an Iron Fence before spraying CF Foam?

A non-reinforced Iron Scaffold can support up to 5 more Iron Scaffolds per side.

A reinforced Iron Scaffold can support up to 12 more Iron Scaffolds per side.

So if you want to spray more scaffolds at once, yes.

Quote from IKilledTheDevil

While that's go to know, what I meant was is there any benefit to damage residence?

Nope.