Interesting, the Revo 16 has been the only Hobie that I couldn't get to edge. The others, possibly because they have asymmetric hulls, seem to edge reasonably well.
Regarding weights, Most of the Hobies (including the Revo 16) pick up some hydrodynamic lift in the forward half with speed. (usually above about 4 MPH). If the bow is allowed to lift clear of the water, it limits hull speed by effectively shortening the water line length. Accordingly I almost always use weights in the bows of the boats to counter the lift. The Revo 16 gets about 5# to 8# (rubber coated dumbells work well/ my friend uses a 7# rock wrapped in a towel); the Revo 11 usually gets 10# to 13#, depending on expected speed. If seems counter intuitive, but adding weight to maintain LWL actually adds speed. To calibrate this, you need a partner to spot your bow at different cruise speeds to establish the best weight.
I have a lead filled drivewell plug (buckshot stabilized in a slurry -- weighs about 25#) for soloing in the back seat in the tandem Oasis. I notice that the very low placement does add a noticeable element of stability to an already stable boat when sailing. You can adjust the weight by your choice of fill materials; if not for stability, a bag or other container of water can be used and doesn't have to be carried beyond the water's edge.
In all cases, adding appropriate amount of weight to keep the boat "on its lines" is advantageous. Maintaining the proper hull posture more than compensates for the small weight penalty. Whether adding weight to increase edging is possible or worthwhile, I would be a little doubtful but haven't tried it.
PS If adding weight to the drivewell plug, making a simple rope handle on top makes it much easier to carry and insert / remove.
Note -- if you carry much gear, where you place it affects your boat's stability and speed. Stowing some items forward can be beneficial in that way.
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