When I took my CT5-V Blackwing to Tapout in 2023 there was no aftermarket support of any kind, until Scott decided to make one. Car got every part developed and tested on it and it ran like a charm. It was even used later on to be the first tuned Blackwing period, and post Tapout tune the car was smoother and more responsive.
Two years later I decided bolt-ons were not enough and made it my project to build the motor. I let Scott know my exact build months before finishing so that i could have a base tune ready to go. One day I email Scott saying my build is done and i need a tune. He sent one over within minutes as he already started working on it back when i just first mentioned my build. And to top it off each time it was tuned the car drove smoother than stock. Everyone who has driven my car is blown away by how the car drives like a factory stock car, despite having a built motor and aftermarket camshaft.
Cannot stress enough how great the customer service and communication is. I have close friends who have spent 10-20 times more at shops who then wait days between replies to catastrophic failures. Meanwhile I show some intent on a motor build and have a tune ready to go. Cannot recommend enough