Would you sign a jct contract with no construction issue drawing in place and the contract still refers to tender drawing and a scope of works that is very broad sweeping statements in it language
No. Or perhaps, not unless there is a clear recognition that this is not a fixed price contract with a proper price and scope to be agreed. In other words, if this is set up properly as a two stage process and an employer wants to involve a contractor early in some form of ECI then yes this can be a good idea. If it is an attempt to short cut proper, reasoned and thought out procurement then the risk is going to be high and difficult to quantify.