Linear Regression for Combo Charts

Qlik's in-box Combo charts currently lack the option to add a trend line (Linear Regression)

If there was a functionality where we could select measure to which we want to apply trends and then select which type of trend and change display settings - that would be really great!

The current option (in-box Qlik Sense functionalities) is to use linest_m and linest_b functions in a measure, but it gets complicated very soon and there is no way to control it's appearance either.

Our business associates have a critical requirement for Linear Regression.