A deep striking Trygon Prime can provide you Synapse in your opponents deployment zone easily if that is an area of concerns, plus their Assault 18 shot can maybe make use of your proxy models with a chain gun ;)
Having Crushing claws and TL Dev's with worms make your fexes make them ok at shooting, and ok with assaulting armor.... but that's it. Having fexes with 2 TL Dev's will make them awesome at shooting, so you can keep them at shooting. Giving your fexes with crushing claws a pair of Sy talons will give them an extra attack in CC, making them better in CC. However, if you plan on using these fexes for CC, and don't forsee your opponent having high armor, lose the claws. All it does is give them +1 str and armor bane considering they already hit at AP2. Str 9 should be enough to take out light to medium armor, only land raiders and monoliths would give you a hard time. Save the points, lose the claws, and use the points to give them regen, or bio plasma, or adrenial glands, whatever you prefer.