I have an idea to use agent of dune harvesting system, master of dune influence indices and great house management system together, but need some insight.
In master of dune, you do a spice harvesting between each chapter. I decided that each chapter is equal to a quarter. So 4 spice harvesting a year.
So Instead of doing house managing only once a year, you manage 4 time a year, each quarter. Divide your resources and wealth and upkeep income by 4. Every venture need 4 quarter to be accomplished. Each quarter, you have to paid 1/4 of your upkeep and receive 1/4 resource and wealth + your spice harvesting modifier ( between -10 and +10 wealth per quarter) . Venture price are divided by 4 but need 4 quarter to accomplish. So, it is possible to stop a venture half way and start something else. Gamemaster decide if some wealth is lost in the process.
This way, it is possible for you to put a venture on hold if you lack the wealth and decide to put your wealth on something else. Of course, after too long or depending on the venture, you may decide to the player lost something in the process.
If you lose too much on spice harvesting, you will have to stop some venture and put them on hold or replace them with something more important. A venture is complete when you are able to pay 1/4 of the price 4 time.
The meeting for spice production is taken place on Arakis and depending on what happen there, player have to go their planet and change the budget. They may not want the planet to know that thing is going bad on Arakis or vice versa and change planetary decision with false justification to hide what is happening.
I am open to any idea to make this better !