Add cross-framing under toilet?

As part of my little project I'm replacing a small square of rotted floor under a toilet -- a double layer of 3/4" ply, in fact -- spanning about 14" between parallel joists.

Do any of you routinely install cross bracing to span between the joists for a bit of extra support under the toilet? It seems pretty beefy without, but I'm curious about best practices.

Ply is strongest if it spans at least two bays (i.e., attached to three joists). So, since you'll have some edges unsupported, consider blocking along those edges.

I agree with jad's comments. I have found over the years, that for a drywall repair, or a flooring repair....a bigger patch is actually easier, stronger, and ends up better on the cosmetic front.

A 14" square of plywood, just supported by a 3/4" lip at the joist, will be prone to sag along the open edges,and pry up on the supported edge.