Can we dynamically change per car overrides?

I have created a shift indicator for Forza Horizon 5, and I currently use the up and down arrows on the keyboard to temporarily change the desired max rpm.

I can permanently change the redline rpm in the per car overrides, but this is a tedious process. I need to shut down the overlay, go to current car, edit, restart overlay.

Is there any way to set the overrides with javascript? Or maybe a different way I could keep these changes beyond just the current session with the current car?

Thanks

-Milky