I think the problem with kids+social media in general will always be: allow them flat and accept all risks, or restrict them and risk that either the kids use them on concealed devices obtained through friends, therefore say goodbye to their trust towards you, plus even less chances to supervise their use, or they actually don't use them and hence are discriminated by their peers for not being online or not carrying that shiny new device every cool kid today has. If you want to restrict the use your kids make of social media, you should bring them to a school where cellphones aren't allowed or where there is strict control over their use, possibly also outside of class, and where they're encouraged to find many alternatives to have fun, ie they should be immersed in a different world otherwise they would be treated as different. Any deviation from what is perceived "normal" behavior among their peers will turn against them in the form of discrimination and bullyism. Being discriminated by peers seems ridiculous of a problem to us adults, but can severely damage the kid self esteem for life, so don't underestimate that danger.

This aside, I can't be of any help with experience; I became well aware of all those difficulties very soon (having a shitty life roughly from 5 to 35 helps a lot) and decided that, although I love kids, a girlfriend and two cats were enough:^)