Cradlepoint needs to be a DHCP Relay not it's own server

We have several locations that are supposed to be setup with cradlepoint but I have had to tell the installers not to set them up because they cannot figure out how to have them be Relay's not servers....  I cannot have random local IP blocks, we have several local static devices like printers and scanners that we use.  I see that in the local admin we can set it up, but once we connect it to the internet, local admin goes away.  I have been told by the install staff that what i want is not possible, I do not believe that.

any help would be great