o2 sensors

Before I started this course, my car (vy ss LS1 5.7) had a custom tune on a side mount supercharger.

my car doesn't like cold starts, it's a rough idle, but good once warmed up and running very rich

My o2 sensors a switched off

Do they need to be on. It's a everyday car.

Switching them on will this affect my tune or change it

really would need help on this one. thank you

I always recommend retaining the O2 sensors for closed loop control where possible. They do a pretty good job of making small adjustments day to day in order to keep your fuelling on point. They aren't designed as a bandaid for a tuning issue though and it sounds like there's some weirdness in your base mapping that you need to address first. I'd start by making sure aspects like your base running airflow tables and idle speed targets are properly dialled in from cold start so the engine will idle properly. From here I'd be making sure the hot idle AFR is on point and then look at the corrections/multipliers for cold starting.