Wheeled Vehicle - How do I get the vehicle to gear down appropriately on steep slopes?

So to make a vehicle (4wd, 13ton, automatic) gear down appropriately on steep slopes? I’ve set it to hold gear for 4.5 secs which allows it to climb properly and stops it from gearing up to a gear that has no torque.

Can I use BP to to set hold gear time to 0 if it’s slowing down? If so how? Or at a minimum set it so dose NOT sequential down gear IE I want it to go from 5th to 1st not as it is now 5 -> 4 -> 3 -> 2 ->1 with 4.5 seconds of delay in between

Here is a video to put it into context:

thanks

bump bump bump - anyone?

Bump - gonna bump this B every week till we have answers - I could post on answer ub but they always get closed with “we ASSUME this has been resloved and are closing it” but how often do they get resolved? I’m going with a good 50% never lol.

Bump 3.5 for the five five