If you want your hives to be robbed by other bees, yellow jackets, ants etc., use a Boardman. Do yourself a favor, cut your losses and don't use them. Go to Home Depot and buy the 2.5 quart clear plastic "Versa-Tainer" paint buckets with lids. Wash buckets and lids when you get home. Polk holes in the lid with a small nail, fill it with syrup, turn it upside down and place it on top of your frames using two 3/8 inch shims. Place an empty medium super on to protect it, inner cover them top cover.
Or, place the upside down bucket on top of the hole in your inner cover using shims, medium super then top cover;
Or, cut a larger hole the size of the bucket lid in your inner cover, staple #8 hardware cloth to cover the hole, place bucket over the hole, then medium super then top cover. That way the bees will feed through the hardware cloth to the bucket lid and you can re-fill without disturbing the bees sticking to the lid or flying up in your face. You don't have to worry about burr comb with this option. It's a little more work modifying the inner cover but it's the easiest in the long run for me.