Adding non-structural wood details to panel

I'd like to add wood arches with a central "keystone"(?) ornament to a desk I'm building, similar to the ones seen in the photo done by a commercial manufacturer. The details will be around 1/4" to 1/2" thick hard maple. The panel will be plywood, but the frame will be hard maple.

Can I just glue them onto the panel and rail, or should I attach them in the center with dowels, or with screws from the inside of the panel? I'm wondering if wood movement would pop the glue joint loose eventually? I'm probably overthinking this, but I'd rather ask than rebuild things. :)

Attachment 451432

I think I would mount them with screws from the inside.