Similar to OnInteract triggers, VRC_Pickup provides a proximity for how far you should be able to reach the object. Changing this value does not seem to affect the reach on the pickup though. I have tried changing it to 0 and 100 and the reach is the same as leaving the value untouched. Another thing I noticed is that for desktop users, the proximity is based on your avatar's size. A larger avatar has a longer reach than a smaller avatar. I have not tested if this behavior is the same for VR users.