No there is no such a flag. Loading is different though. It is possible to have an assembly loaded with missing dependencies (e.g. CodeDom) and you use this assembly just fine as long as you are not calling any method that depends on the missing assembly.
But for compiling I am afraid you will need to fork the code and remove the assemblies manually.
But for compiling I am afraid you will need to fork the code and remove the assemblies manually.