Let me see if I can add anything (dusting off the old “Field guide to airplanes”)
I’d have ruled out the F-15, F-18, and SR-71 type tails as “similar” to the B-24. Twins, yes, but they’re not attached to the ends of the horizontal stabilizers, and these aircraft don’t have a tailboom to speak of. I’d also discount the P-38, OV-10 and Cessna Skymaster types, because they have twin tail booms.
H-tailed military aircraft that come to mind(do the google search yourself for photos): A-10, T-46 a jet trainer that didn’t enter production, and the C-23 Shorts (Sherpa?)
Civilians: Beech 18, Ercoupe, and the Shorts derivatives. Those Shorts airplanes are the ugliest flying boxes I’ve ever seen.
More than two fins: OV-1 Mohawk, E-2 (Naval radar plane) and the aforementioned Constellation.
Good things about multiple tailfins: lower control loads (means less pedal forces in unboosted airplanes) and less vertical space needed, some redundancy.
At first I thought that having the rudder in the slipstream was a good thing too, but after thinking a little, I kind of doubt it. In a low speed single engine out situation, you’re likely to have so much sideslip oscillation that I bet the fin would move into and out of the prop blast, making yaw control more difficult.
Bad things: heavier structure needed to carry the loads, more contol system complexity.
Nowadays, I doubt anything would justify the weight except the “envelope” considerations (like the E-2) and survivability (A-10).
I’ve seen some endplates put on the ends of helicopter horizontal stabilizers (not movable), but it’s always been a band-aid solution to not having enough tail to start with. That’s why they’re being tried on the RAH-66 Comanche.