How about selling patents for monthly income?
How would that work?
You've already implemented disclosing information to MAGMA(?) as a research project. So, selling a patent could be another research project (with minimum man-hour price) that increases your monthly income.
If the total monthly payment has to be equal to the sum of countries' contributions, the patent price can be evenly distributed between the funding countries. Alternatively, the payment can be added to the monthly funding by the country where the company is based (e.g. Russia for MAGMA).
When a country is infiltrated and quits X-COM, there may be something like:
1. For distributed funding, the monthly payments can be recalculated. Will the engine allow it?
2. For distributed funding, if recalculation is impossible, then "Alien Infiltration" description should say that when a country quits the project, it freezes or confiscates X-COM financial assets it was handling.
3. For funding through a single country, "Alien Infiltration" description may say the same about freezing/confiscating or something about a ban for companies on dealing with X-COM.
4. Or cessation of funding may mean cutting all funding except royalties. Can the engine do that?
I think research can produce an item now, but even so, you can only do a given research once.
But if you research a set of identical items, you can repeat the research until you run out of items.