I've added a new "starter" economy to FIRS.
It's based on Vanilla openTTD industries but a bit more spicy with FIRS enhancements and engineering/farm supplies loop.
I feel it adds a lot of versatility to vanilla industries while not being overwhelming.
This also adds an extension to the basic temperate economy. Removes the chemicals mini loop and streamlines a few of the industries.
Late edit:
My idea for an agriculture based economy

The idea is that this should be a simple economy with tight feedback loops.
For the feedback loop you need brewery for Alcohol, but you have 3 industries providing Fruit.
On the other hand you have multiple industries producing food and you can choose which one you like but then each has only 1 type of cargo it needs.
This will create a gameplay where you consolidate big networks around a few hubs, but then you need to have secondary hubs splitting the farm supplies consciusly.
I have a few more ideas for new economies that might be fun, a fun one I am thinking about:
- Water based economy ( a lot of industries to and from water )