Glassing it in would be strong for sure, but you have quite a bit of bracing up there as it is correct? Long as it didn't affect the strength or structure of that area, I kinda like the idea of the sacrificial mounts so it is removable. Not sure why you'd need to, but if the situation were to present itself, you'd have that option. Far as the opening itself, I'd use net or maybe vinyl flap with snaps.
It looks good, like how you radiused the opening instead of just straight cutting it. "Radiused" is what I guess you'd call it anyway? :cheesy: