When I tried to see the cost of a local dealer they said they can do OEM or aftermarket radiator, aftermarket was cheaper by like $300, but they tried to price gouge me last minute on the whole job so I passed using them.Some dealers are known to source aftermarket parts if OE isn't available quickly enough.
It's also entirely possible your aftermarket part doesn't have the design flaw that leads to the topic of this thread, but as @kcjaz experienced often there are other QC issues with non-toyota parts.