Track progress of Goals based on custom measure and not just on success plan or CTA completion

Currently, in Customer Goals there is a work in progress bar based on the number of CTAs and Success Plans associated and how many CTAs/objectives are open vs closed. This is not how we track progress to Customer Goal achievement and is not useful for us. We have added fields for the specific KPI used in agreement with the customer to measure progress toward that goal with separate fields for Actual (current value of the KPI) and Planned (Future value of the KPI) that we are working towards. We want to track progress in % towards that future planned KPI value. The progress bar is nice but it would be better if we could customize the KPI measured in the progress bar using some sort of configuration and inputs from the CSM on starting value, current value and goal value with % to achievement. The CSM would then own inputting the current value to update the % complete so update the progress on whatever weekly, monthly, quarterly cadence.