I believe by default the forecast tool will only use the default amount field.
I'm not sure if this will be helpful for you, but for one of our clients, we used a combination of calculated properties and a workflow to adjust the default amount field based on additional conditions that were related to the deal. For example:
Default deal value was $100
Additional option was $10
New Default deal value $110
While forecasting still uses the default, the default amount was adjusted based on variables.
Again, may or may not be helpful for this situation, but the starting goal was similar so I thought I'd mention it.
I believe by default the forecast tool will only use the default amount field.
I'm not sure if this will be helpful for you, but for one of our clients, we used a combination of calculated properties and a workflow to adjust the default amount field based on additional conditions that were related to the deal. For example:
Default deal value was $100
Additional option was $10
New Default deal value $110
While forecasting still uses the default, the default amount was adjusted based on variables.
Again, may or may not be helpful for this situation, but the starting goal was similar so I thought I'd mention it.