Flyover gradients

Hi all,
Not specifically a digital question but I've posted here as it's maybe more related to Scalextric track past & present and it seems good joints are more critical in digital

I've wanted to keep my new sport track connections pristine & undisturbed but many of you seem to have flyovers by default so think I'm missing out by avoiding them and also crossroads are causing too much car damage. My old classic track had problems with continuity when I switched to digital caused by many years of being reassembled in different ways & often with a flyover.
So, my questions are: Do you just bend the joints at the crest and bend them back if you change the track and what max gradient do you recommend for an SSD flyover?
Cheers
Chris