The embedded KPIs defined with aggregate measurements already provide quite a nice way for the users to personalize what they need, especially to adjust the KPI thresholds:

"…In Finance and Operations, users can use a rich client form to modify a KPI definition that was built and shipped by a developer. Users can also define new KPIs by using the aggregate data that is contained in aggregate measurements. A developer can model a KPI definition in Microsoft Visual Studio and ship it to a customer, either as a project or together with an independent software vendor (ISV) solution. After a KPI is defined, users can customize it at run time"

^{From <https://docs.microsoft.com/en-us/dynamics365/unified-operations/dev-itpro/analytics/analytics>}

However, currently the aggregate measurement KPIs seem to support only the source data fields/columns as the KPI actuals and targets (with some limited modifications like prior year filter), but not calculated fields/measures. At least basic arithmetical operations are still necessary to support measures like contribution margin or ratios. So, please consider enabling the embedded KPIs to have actuals and target measures defined with calculation expressions.

The alternative suggestion has been to rely on the embedded Power BI KPI visuals and create the underlying calculations by using DAX expressions. I do like this approach of reusing PBI capabilities and the power of DAX.

However, the standard PBI KPI visual and even "Power KPI" and "Power KPI Matrix" visuals still do not support sufficiently easy control and maintenance of multiple KPIs by the (key) user. That includes KPI threshold percentages and interpretation (higher is better, lower is better, closer is better), though what-if parameters provide a partial workaround…

So, enhancing the existing aggregate measurement based native KPIs with basic calculations may be a relatively 'low-hanging fruit' to provide multiple KPIs to multiple users in both embedded and highly personalize-able way.