It doesn’t work for all, but we limit screen time because that is what works for teen DSs. Weekdays outside of using screens (other than phones) for school work, whilst travelling or during treatments for a medical condition/physio DSs can have 1 hour a day. Weekends are more relaxed as long as it’s not at the expense of other things.
DS1&3 aren’t interest in their phones. DS2 would be surgically attached if allowed - we don’t allow him to have his phone overnight (it amazes me that he gets messages at all times of the night) or 30 mins before bed.
DS1 still co-sleeps for at least part of the night. We have tried various lighting, a 2 way monitor, walkie-talkies, doodle book/pillowcase, worry book, tents, weighted blanket, music, white noise, dream pad pillow, ear plugs, teddy, relaxation, various apps, brushing, audiobooks, meditation, adapted version of gradual retreat, elastic band method, sleep clinics, medication… Things are better than they were, but nights are still difficult.