yes, what they said - you might try pumping a good seam sealer in there, but paint will likely always crack from the flexing so don't try to get it rounded like the top edge, use a tool to smooth it concave so it doesn't show
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics