The older Polaris hydraulic brake can be fit to a Phazer. A plate has to be made and some holes drilled. I have one that was already modified when I got it. I am not able to post pictures and I know without them that this does not help you much.
If you could use a spacer to put the handle closer to the bar it might help.
The Phazer/Exciter brakes were never real good. To get the best performance, put on a new cable. An old cable that moves hard will increase the force required to apply the brakes. It may seem that it moves fine, but under load the resistance will increase greatly. The same applies with the actuating screw assembly. Take it apart and clean and lubricate it sparingly with lithium grease. If it is not the self adjusting type, keeping the adjustment very tight helps a lot. You may also want to put new pucks in, the material was changed over the years.
Ventilating the rotor will also help.