So, DE has a feature called Groves, which are collections of trees which are 1 large selectable and gatherable object. There's a few interesting things you can do with this, like make an "underbrush" aura which makes units move slower through them, have less accuracy while shooting in them, etc. Also, as one selectable object you have fewer things to keep track of and also conceptually they make sense in that forests were valuable sources of resources, not just individual trees. There are still individual trees (stragglers), but they aren't the sole source or primary source of wood, the groves are your primary source of wood.
Now, also in DE you can build Storehouses and Farmsteads outside your territory. This creates a soft concept of "weak countryside; strong city", where a lot of raiding happens outside of the home territories of the players.
But instead of suggesting EA adopt DE's features, I've come up with something specifically unique that the core game could adopt. It takes the DE concepts and pushes them forward a bit.
So, imagine the map has these Forests and Farmland areas. Forests would be a collection of large wood-bearing objects similar to DE's groves with a Gaia Lumber Camp nearby, while Farmlands would be large open areas of furrowed land terrain with a Gaia Farmstead nearby or centralized to it. The basic game still doesn't let you build Storehouses or Farmsteads (I would rename the player-built object to Granary to distinguish) outside your territory, but it does let you capture these Lumber Camps and Farmsteads which are outside your territory. (the overall concept is similar to the capturing Stone Quarries and Metal Mines idea, which are resource bearing objects outside your home territory). So, instead of the old "slotting" concept, you just capture these Lumber Camps and Farmsteads which are already there.
Forests become "renewable" sources of wood (it regenerates wood over time if not reduced to 0), but slower to gather than individual straggler trees (which don't renew) that you find inside your home territory. You can still build farms in your home territory, but those on the Farmlands are much more productive.
Lumber Camp mockup:
Capture the Lumber Camp dropsite (Yellow) and now you can gather wood outside your territory.
Forests are made up of Groves (Red-cartouche footprint; Blue-circle footprint) and can be depleted, but they regenerate wood over time, faster if left alone. Groves have other attributes, such as they can be "garrisoned" by some civs' soldiers for an ambush effect, and they also have auras that cause units to have lower vision and movement speeds within their footprints.
Straggler Trees (Green) are gatherable, but do not regenerate and can be built over by player structures (the tree disappears).