I agree with Jeff. It is rare and I reckon it’s worth a shot.
Reinstate his existing account (he should still be accountable for his past behaviour and you don’t want your other members to feel tricked or let down if it goes south again), keep a close eye on him but don’t pre-emptively judge him.
I’ve done this a few times – sometimes it’s been a huge success, sometimes it’s been a success for a while and then gone downhill again, sometimes it’s been a failure. I learned something every time, so no regrets.
You’re human and that qualifies you. Over the last 20 years (jay-sus) I’ve transitioned from community member to volunteer moderator to volunteer admin to paid CM to better paid community consultant to managing a team of some of the smartest community professionals I’ve ever met and I’m not qualified. Don’t fall victim to impostor syndrome.
If you have questions, ask them here. It is literally our job to support you in this stuff.