DD is turning four soon and would very much like to ff. She is 39 inches and 37 pounds and currently in a radian.
Is their a compelling reason to continue to rear face at this age?
Technically it's safer to rf at any age.
But, it is significantly safer to ff a 4yo then it is a 2 yo. Their bone development is more advanced. I would have no qualms about turning her if it makes your life easier.
So, marginal increase in safety but not as compelling as a younger child.
Pretty much. I'm a CPST and I'd be fine with a 4yo in a well-fitting forward-facing harnessed seat with a top tether.