I think INT would be more clear/useful if it was applied to the most high impact intervention of the cause, rather than the cause itself. Because a cause can be low in scale and neglectedness but high in tractability if there is one very high impact intervention that has been ignored or simply isn’t known about. Or vise versa – the scale and neglectedness could be high while it’s best intervention isn’t that promising (thus the cause has low tractability). So the importance in this usage would be that of the best intervention of the cause being successful (including side benefits like gaining knowledge applicable to other areas), the tractability would be the odds of it being successful (estimated using the strength of the evidence for the intervention), and neglectedness would refer to how much attention that top intervention has received, as opposed to the cause in general. I think this is basically what you are arguing but phrased differently.
I think INT would be more clear/useful if it was applied to the most high impact intervention of the cause, rather than the cause itself. Because a cause can be low in scale and neglectedness but high in tractability if there is one very high impact intervention that has been ignored or simply isn’t known about. Or vise versa – the scale and neglectedness could be high while it’s best intervention isn’t that promising (thus the cause has low tractability). So the importance in this usage would be that of the best intervention of the cause being successful (including side benefits like gaining knowledge applicable to other areas), the tractability would be the odds of it being successful (estimated using the strength of the evidence for the intervention), and neglectedness would refer to how much attention that top intervention has received, as opposed to the cause in general. I think this is basically what you are arguing but phrased differently.