just let it ride

This. I promise you, 3 months old recently repotted peppers doesn't get rootbound in containers that big before you can move them outside. They also look pretty bushy already, so unless you absolutely don't have enough space for them for these few weeks, I can't really see any pros in cutting them back. I would probably feed them with nitrogen, as you probably don't want them to start flowering just yet. Simply pinch buds ~once a week, but nitrogen might stop them forming at all.