Controlling the Traction Battery Usage

I've been digging around the site, but the closest I can find, which doesn't directly do what i'm looking for is the BMS device, which is long since gone. Extra SOC would be great though.

I live in CO and routinely drive into the mtns. I've noticed that when the battery is at a high SOC after going down a hill, it likes to use that charge very quickly. I watch the Amperage and it pulls 50 plus Amps until it gets to 50% or so, then it backs down to the normal 10/20A. Toyota doesn't want it to stay in that high SOC for long I guess.

What I want is the ability to say, no, I only want to use 10/20 Amps of the traction battery so I can spread it out for the whole hill.

I also want the ability for when I'm headed to the mtns to charge my battery up to a high state of charge so i can utilize it for the uphill.

I know that Honda Insight owners have a device that can do this. Any thoughts? I can't be the first one who's thought of this.