Even that will not protect it 100%. My chassis was even bent in the front, before the 3 posts where the whole bulkhead construction sits.
Plus, I would rather get rid of these battery posts, and making a topdeck so high will probably touch the bodyshell and be in the way of electronics etc...
You would be surprised how much stiffer it gets 'longitudinal' (is that the correct word?) by simply using the spacers under the brace, it creates a structure like a real topdeck.
If you still bend the chassis permanently with these braces, that would equal a broken chassis if it would be plastic. You can't make it bulletproof