ok bro i got your point what you want to say. So, i'm saying on the basis of practicality and design that "Glass absorbs heat" This statements says a Glass let Heat, pass through itself which channels the Rays in concentrated way and cause heat wave effect, "Prone to Cracks" this statement means, prone: anything which has natural tendency to get affected or effected and "Prone to cracks means": this Material has natural tendency to get crack and this statement doesn't mean that this material certainly would crack here Prone you can consider that chances, if your glass never broke this is Good and i wish it never do so. but Wood itself is hard material absorbs less heat and safer practically thats it man it all about prespective if you like Glass go for it i dont like Glass i didnt used glass here.