Just used v4, and you can mod the Meridian points fine but the other options cause your Experience to freeze meaning you will not be able to unlock ANY abilities (outside of main mission unlocks). Thanks for the efforts so far, would love to be able to effectively mod Skill Points soon.
Had the same thing happen to me unfortunately. Meridian Points work quite well, but the other 3 options of Power EXP, Exp upgrades, and Skills Pts do not work still, and cause your EXP bar to freeze.