Slic3r air prints on raft

I've been trying to print a part that has supports (Towers) starting on the bed. If I use a raft, the raft prints 1 base layer of about 20% fill, then does hex for 2 layers of about 5%. Layer 4 is when the support towers begin, not on layer 1 of the raft. This causes the first layer of the towers to "Air Print" if they do not perfectly align with a crossing path of the hex. Even if they do make it onto the hex layer, they are totally unusable as they have no vertical stability at all. Am I missing a setting, or is this a bug that needs to be addressed? The two pics show how the first layer of the tower supports are barely attached by 2 points on the raft hex.

You must have a fairly large Pattern Spacing value on the Support and Raft settings. There's no real reason for it on this since the interface is with support material and you're not looking for a shear plane there anyway. You could probably even use zero with no ill effects.