Graphics update

it would be nice if the altimetry graph were more visible during the routes

See HUD Customisation

can you explain to me how to better visualize the elevation map

Sorry but you can’t. That’s a thread in the Feature Requests (i.e. users asking for new features) forum.

The best thing you can do for now is to check out the elevation profile in advance with a resource like this - Complete Master List of All Zwift Course Routes - Zwift Insider