Just curious why you are suggesting to open a PB coil if you're trying to fill a vessel. You don't want to add heat while trying to transfer cryogens.
Best practice isn't generally too sophisticated, they're generally not even filled with an insulated hose.
If you really wanted to do this with optimum efficiency, use a VJ insulated transfer line to minimize heat flux and boil off between vessels. Size the VJ to minimize flow losses so the pressure differential between supply and receiver vessels is also minimized to reduce flash losses. Generally, those things aren't done because the cost of an optimal system outweighs the benefits.