When I was testing mine, yes that was the way it worked ... in fact I puzzled for quite some time with what the B/L marking meant ... then I realized with just one door open it probably meant BiLevel
This is the product I used for the big seal
https://www.homedepot.com/p/Frost-Ki...EF41/310655227 Doesn't appear they make this same stuff in smaller sizes but with a sharp razor blade and some patience it could probably be cut down and used in other locations.