I have a very thin wood laminate around that I did not think of until you mentioned scratches. But contact paper would take care of that or how about taping camping photos on top. I am not worried about warping since I have had that Plexi for a couple of decades and it's flat. I have plenty of scrap such as beautiful fir but it would weigh too much. I like bamboo and it is light but scratches also. I like the look of the Plexi and will put up with scratches or cover any with photos if they look bad.
Cathy. Floating Cloud
"Live in the sunshine, swim the sea, drink the wild air.... "