I'm splitting up Plantation into 3 different improvements. I had already split-off Vineyard. But after adding some new luxuries and new techs, it seemed useful to split this up even more. Here are all the base plantation resources plus some new ones, with plantation type and prereq tech:
Vineyard (Zymurgy): Grapes->Wine*
Plantation, textiles (Weaving): Cotton Trees->Cotton, Silkworms->Silk, Dye
Plantation, orchard (Irrigation): Bananas,
Berries, Citrus Trees->Citrus, Sugarcane->Sugar
Plantation, exotics (Calendar): Incense, Spices,
Tobacco,
Tea,
Poppies->Opium
[*Arrow notation used when the map resource has a different name than the resulting trade resource.]
All of the tech prereqs are 2nd tier requiring Agriculture, with Calendar also requiring Writing. One nice thing is that you can improve/trade more of these without Writing now. Bananas and Berries are "bonus", meaning good food yield but not tradeable. All others are luxury.
Also, I never could figure out a graphic for Reagents (never knew what they were exactly). So I'm replacing that with
Moly and
Cinnabar->Quicksilver. Moly is a magical herb that you can see only with the Witchcraft policy, improved by Gatherer's Hut. Cinnabar is visible with Alchemy and improved by mine. Both have a sparse, strategic distribution and are tradeable. They don't allow any units (for now) but will be consumed by some new buildings that are enabled by Alchemy and some arcane techs. Quicksilver's main function is to be transmuted into other things, like gold or silver, with appropriate tech and buildings.
There may be more additions later. But these cover all my immediate needs for balance and new mod mechanics.