I'm not familiar with the Mahu Je or Dragonshard Pommel, but I'm personally inclined to say "Doesn't work with this version of the soulknife". You've already got a effectively +11 weapon, which can either be +6 with +5 enhancements, or +1 with 10 enhancements, +2 of which you can change on the fly for things like bane; or holy to bypass dr and hit weaknesses.Only problem I have is something like Mahu Je (or however you spell it; that legacy weapon that can transform into a mindblade), plus a Dragonshard Pommel could potentially grab you any enhancement onto your mind blade; I especially like me my Aptitude Fists (for only about 2000 gp, and which can't be taken from me).
I could maybe see the legacy weapon thing being adapted so that your mindblade can gain special legacy weapon powers (if I recall correctly they get some neat random abilities beyond just enhancements, like casting some spells x/day.), but nothing to stack on a more weapon properties than what you've already got access to. Instead of looking for ways to make your stick bigger, a soulknife should be looking for ways to spend that 200k gold he's no longer having to spend on a weapon.