And for a follow up question, aren't limas a one time crop? As in, they set all the pods at once, then they're done? If so, wouldn't bush limas be more productive, per square foot of garden space?

Bush Baby limas can be productive, large limas are more tempermental. Usually like bush beans,one crop is used for production. With patience and a long season, they will make up to three sets. There will be a several weeks between sets tho.Can Green/Thorogreen has been my best performing bush baby lima. Pole limas are pretty much everbearing. Mezcla has been the top producer for me. Pinkeyes, Big Boys, Zipper have been consistent performers for me. Of course when you are growing for production, you need to be aware of the preferences of your customers. White Acre is not quite as productive, but in high demand here in Georgia and of course there are folks who want Brown crowders like Mississippi Silver.