Need Help Creating a Custom flowMode Rule

[Starwhip]

Shortly, I should be releasing the first update of an overhaul of an old mod I developed last year, which fell into disarray. Though this is not a necessary factor for the first update, it is going to be necessary in the future. I need to, through some means, change how the stock SolidFuel resource behaves flowing through a ship.

The base functionality of this mod consists of a series of solid fuel booster segments and various nozzles to create functioning booster setups that are not bound to any one particular size (as they are in stock), like this one, which consists of a central nosecone + 2 fuel segments + nozzle and two radial assemblies with only a single fuel segment each.

Modifying the SolidFuel resource flow to STACK_PRIORITY_SEARCH half-solves the issue. It allows the booster to fly as one would expect the system to fly. Which is pretty fast.

But, fuel lines attached to the outer tanks and run to the inner allow asparagus-style staging. The SolidFuel resouce has a transfer rule of NONE, but that seems only to apply to the right-click menu of a part with SolidFuel.

Here is what I see needing to be done. I need to create a new flowMode for the SolidFuel resource to use, which can draw from the stack above it, but not from radial sources. I have coding experience in Python, Java, C, C++, and C#, but I have not found any way to get to the necessary classes/definitions to create this new rule. Help would be appreciated.

[Azimech]

Are you absolutely sure it can only be solved through coding?

[Starwhip]

4 hours ago, Azimech said:

Are you absolutely sure it can only be solved through coding?

No, I am not. If you have any ideas as to another method I'd love to know.

I found something the PartResource Class Reference, which might be what I am looking for, though I am not sure. It seems the stock fuel resources have additional data, other than those depicted on this reference.