[JRTJH]

My understanding is that Keystone moved away from the stamped steel floor registers and started using plastic ones to help prevent burned feet. Apparently some people complained about infants/toddlers standing on the floor registers near the furnace and getting burned by the "heated up steel registers"....

For most of us, it's probably not an issue, but if you do replace the "fragile plastic registers" with steel or cast iron registers, just be aware of who might be standing on them without realizing they do get hot.