Griddle insert size?

I have a blaze 40” 5 burner grill and bought the full size little griddle off bbq guys. It covers 3 of the 5 burners. It’s fine for doing burgers but way too small for fried rice or doing multiple items at the same time. Eventually I’ll wind up getting a black stone bc it’s alot easier to scrape and clean than this griddle insert with the grease channel in the front.

Be careful when frying smash burgers. Lots of grease... If too much, the grease will overflow from the catcher and you'll have a fire on your hands.

Happened to me when I used a griddle for my BGE. Had to close it up until all the grease burned off.

Burgers were toast.

Ended up getting the full size insert. Figured I can always use a section of a big griddle, but can't add sqft if I don't have it.