I'm certain that this issue was raised at launch, and I do recognise it's a moot point with the (likely upcoming) 2025 cars as they don't have this system, but because it's such an integral part of t...
Ideas
Real drivers had Boost Fill-Up Lights on top of dashboards so they saw how it got filled and when it was full. That row of lights lit-up with amount of boost was charged in, last lights in the row are red to indicate that boost is full and will be deployed next time when going on the throttle.
In this game those lights on top of dashboard is set to show rpm -> gear change up places which is wrong.
No need for this double system as display in cars inside steering wheel rim (visible in cockpit -> helmet view) turns fully red indicating gear change up places.
Now in the game we are forced to have instrument cluster enabled and have to look too often into right bottom corner to see if that tiny boost circle got filled.
In Hyundai Rally1 Hybrid the boost fill-up light bar is to the right near A-pillar on top of dashboad (idk about Ford how it's placed there)