What dermaroller size should I use for hair growth without scarring? If 1.5mm, how often should I dermaroll to avoid scarring?

If I use a 1.5mm, how often should a dermaroll before the next session to prevent scarring? I am thinking of dermarolling 1x every 7 days medium intensity with a 1.5mm roller and applying anti-inflammatory agents like castor and olive oil. I just want to know if: 1) A 1.5mm roller will cause scarring 2) If it doesn't, will a 1.5mm cause scarring if I dermaroll every 7 days based on the aforementioned. I would appreciate it if you can please answer these questions directly without ambiguity.