On Wednesday, July 24, 2019 at 12:58:40 PM UTC+1, Bill Wright wrote:

Speak to the plasterer. Obviously. Get his agreement.

With the way this project is going the appointing-a-plasterer stage feels almost as far off as selecting-soft-furnishings!

If there's no hard and fast rule about what is acceptable then, yes, it'll come to what the plasterer says. If it's a showstopper for them (unlikely as I imagine plasterers have to deal with all sorts of issues caused by the numerous trades before them) then I'll just go round each proud box and chip sufficient material away from behind them. If I can avoid that faff though I will.