i have alot of plate steel lying around. cut a piece of 3/8" (~1cm) to fit exactly in the oven, put stainless handles on it (its probably 30lbs/14kg) to lift it in and out. cleaned it off well and seasoned with avocado oil (I guess flax is better, but it spoils)

takes a long time to heat up, but when it does pizza cooks like its supposed to, and the oven temp springs back quickly after you close the door.

inexpensive and pretty durable. highly recommend.