Some vehicles repurpose shift paddles as a way to trigger regen braking. But they're pretty gimmicky and not really useful for driving. If you want to use regen in a vehicle that supports it, the brake pedal does that. And when regen is not enough, the hydraulic brakes are also used. But a "sometimes brake" pedal that only support regen sounds like a bad idea. Vehicle controls as essential as braking need to be consistant in how they respond to input behavior.

I've been driving a Chevy Bolt for over 8 years now, and I regularly use the regen paddle. I drive in "L" mode, which engages partial regen when the accelerator is released. When I need more slowing, I pull the paddle, and that increases the aggressiveness of the regen. I only press the brake for quick stops, or to hold the car once it has stopped.

I also use the built in "hilltop reserve" feature, which limits charging to 90%. This ensures that there is always regen resistance, and therefore a consistent experience.