Saw something clever a few weeks ago. Nolan Hirte from Liar Liar cafe in Melbourne bought some Anfims to run next to his Roburs a while back, but wasn't overly impressed with them. He has replaced his Robur dosing chambers with Anfim dosing chambers and has also put a timer on them. He said that the Anfim timer was only OK because the Anfim is so slow, so he had to source a different one. So now he gets to have the clean dosing of an Anfim with the speed, stepless adjustment and longer pour of a Robur! Pretty cool, I thought.
The grinder in question makes brief appearances in Syd Low's fantastic photo set of the Victorian Barista Championships: http://thelows.org/09VicBarChamp/
If you didn't want to hack up your Robur, I guess you could put an external timer on one of the new Roburs with a better dosing chamber, or you could do some sweep/spout/grid mods to your existing Robur. Another way to go is to buy a BNZ conical grinder and modify it to have stepless grind adjustment.