i do this because my client are simulating physics and are trusted by server for their location, what they touch, what they collect, etcc, physics is disabled on server side
client are trusted by server because its a coop game, we wont care about cheater, because cheating with a friend in a coop game is not needed, friends would be agreed on cheating or not ^^
but doing this, i am now stuck with this scenario where client bump into actor place in level, they cant communicate with server trhough this actor 
maybe there is a way to do a server authorative game with player controlling a physics object but i always failed in differents things, in some case the delay in input is too bad, some case desync happen, etc i couldnt do it, the delay ruin everything.