I've got a JC Higgin's Jet Flow with a beehive springer. I'm 240 pounds and the springer works fine. The only way it would bottom out would be if I was riding down a very steep hill, moving very fast, and then hit a bump unexpectedly.
I don't know tightening any of the bolts on the lower front fork assembly would make any difference because it's worked well enough I haven't had any need to mess with it. Unfortunately I'm moving halfway across the country next week and I've already packed my tools, otherwise I'd wrench it up and tell you what happens.
50's era Higgins were built like tanks, and so were the beehive springers. For a tandem ride in what I imagine would be a casual setting and leisurely pace on smooth terrain, it should work fine.