Ultimate Intrigue has a feat called Starry Grace that should add Dex modifier to damage. However, the data in ui_feats.lst only lists the prereqs and description, not the benefit.
Starry Grace CATEGORY:FEAT TYPE:Combat PREVARGTEQreStatScore_DEX,13 PREABILITY:2,CATEGORY=FEAT,Weapon Finesse,Weapon Focus (starknife) PRETEXTex 13, Weapon Finesse, Weapon Focus (starknife). DESC:Your quick and free starknife motions allow you to make deadly dexterous attacks. SOURCEPAGE.92 BENEFIT:When wielding a starknife, you can add your Dexterity modifier instead of your Strength modifier to that weapon's damage. The starknife must be one appropriate for your size. You do not gain this benefit while fighting with two weapons or using flurry of blows, or any time another hand is otherwise occupied. In addition, if you have the panache class feature, as long as you have at least 1 panache point, you gain a +5 bonus to your movement speed on your move action after taking an attack action with a starknife or on your Spring Attack or charge with a starknife.