If you can find one, a Nomadio React has Tank Mode built in
. Haven't tried it myself but it should work
Brian's idea would definitely work, but could take a lot of time to fine tune the feeling of the brakes.
SH Z-Car, Custom Crawler, 8s Savage,
12s XTM XLB 1/7 buggy,
4wd 4-link rear/IFS Pro4 truck,
Custom Hyper 10 Short Course,
Belt-Drive Mammoth ST 1/8 truggy, 4s 17.5 MM Pro HPI Blitz