I also have a LPKF circuit board plotter in the lab.
We use it also for 0.5mm RF boards with 0603 SMD's and SSOP's.
It works well.
If youre going to mill RF boards here's one TIP: after milling, the basis material is coated with many tiny copper particles (you can see them under the microscope), so dip the board into a soft etching solution, just to solve those copper particles. If you try this on only one half side of a test board, you will see the result under the microscope.
If there's a possibility to plate the board with silver do it !
I always use much soldering paste, befor placing the SMD parts.
So you will not need ANY solder, the solder plating of the parts is enough and the solder trickles onto the copper track.
After this, the board looks dirty, but using a cleaning lubricant or foam makes the board looking like a professional one.