Phil, it's always a personal choice exactly what you choose to submit as documentary evidence on specific issues. Mostly in support of showing genuine relationship etc. or to support some complexity or uniqueness about the application.
The mandatory documents are, of course, a given.
Phil, what's you thinking behind supplying documents that are not mandatory ?
Although as I say it's a personal choice, always be cautious about supplying anything that may result in unnecessary scrutiny.
Just my thoughts