How would the multiple INSS bonuses work with LD?
If you mean a map that has INSS built into it, no.
If you mean using the INSS Bonuses mod, yes. From the mod description:
Adds a really simple, INSS bonus system to any map.
Players will get income based on the amount of territories they own of a bonus and the bonus value. The more territories you have in a bonus, the more income you get
Imagine a bonus which contains out of 5 territories and with the value 3, then you'll get the following income
1 territory = -1
2 territories = 0
3 territories = 1
4 territories = 2
5 territories = 3
This mod does work correctly with LD enabled.