Intake cross over blockage or not ?
I have mine open on my RPM intake (non air gap) and it's nice because it warms up fast enough so that not having the choke hooked up works out ok. I just feather it and keep the rev's up for about 30 sec's and she settles down. A good carb will help make up the difference on warm up too. That's what I've found anyway...
On the flipside, it does work as a hotbed under the carb for putting extra heat on your fuel, which is never good from a performance and efficiency standpoint.
One of those pick your poison things I suppose...