We had this for a while with DD1 when she was a similar age.
Pick one method and stick with it - the more different things you try the less consistent you are and the more he sees it as a game or a way of trying to push the boundaries.
We did this:
Dinner, playtime, upstairs for bath, story and bed (no coming back down at all).
Kiss and cuddle night night, then in bed, glowlamp on and potty next to bed. Lights off and door shut.
If she came out, we didn't even speak to her, and we hardly looked her in the eye. We just steered her back to bed and tucked her in. Repeat ad nauseum. (Very tiring and frustrating but it doesn't last long).
She pretty quickly realised that coming out of bed gave her absolutely no benefit at all. No chat, no negotiations, no cuddles, no promises of treats for staying in bed. It was non-nogotiable - it was bedtime and that was that.
We did the same in the mornings - if she woke early i.e. before about 0600, and came in to us she was steered back to bed and told it was still night time (blackout blinds in her bedroom helped with this). She had a potty in her room and a water bottle and I would leave some books on her bed.
So I think the Ignoring method works well but you really have to stick with it, it won't change things in a couple of nights.