I'm not aware of anybody using OBDEleven to improve performance of the car. I have heard that it's possible to adjust the power steering effort, but that's about it. You can use it to enable a few electrical tweaks though (using the remote to raise/lower windows, etc.).
2021 Tesla Model 3 SR+, Pearl White Multi-Coat, Black interior, 18" aero wheels, no FSD
2019 e-Golf SE, Pure White w/ DAP and deAutoLED H7RC HID's (SOLD)
2016 e-Golf SE, Pure White w/ Ed's Golf R Replica HID's (SOLD)