Huuuge ears on all foam

I'm back again, this time with ear questions!
I've seen several entries on huge ears, but a lot have to do with attaching them to resin bases or standard foam bases. I've got a bit of a non-standard head.

My pepakura pattern method worked like a charm, but the ears are gonna need more finesse to their construction. These ears are 2 feet along the longest edge, and I'm attaching them to a huge head of foam as well.
The first issue is, that while the foam head holds itself together great, it's still got some give to it, as pictured.


I plan to reenforce the inside of the head with some "boning" of another layer of foam, or a slightly thicker foam, but I still worry about the weight of the ears creating a dent. Especially since theres gonna be big fur tufts on the inner ear too. Also considering I'm gonna need something hold it to my head inside, how the heck do I "anchor" anything to the foam like this?

Attaching them is a bit of an issue too. I already tried gluing them on regularly and it wasn't working out too well, lol. Would cutting a gap and using a thicker foam at the base still work? Or maybe I should use a plastic or something? The actual logistics of "getting it to securely stick" is still lost on me somehow.

My other issue is that even though I curve the ears along the base (you can see my guidline a bit in the one photo) the top portion of the ears still resist curving a little bit, and kinda "flatten out" towards the tips.

Whats a good way to force them into shape? Here's my pattern for the ears by the way, for reference.

It works great and getting it to 'want' to curve, but still not effective enough that it doesn't need some kinda re-enforcement.