TechDudeIt definitely would affect rocket jumping! If you are changing the geometry of the projectile impact box you are bound to affect several types of jumps (wall climbs being one easy example).
is splash damage itself calculated using the bounding box then? i thought it just used some fixed point in the centre of the model since rockets shot slightly downwards on a wall still propel you upwards and not directly horizontally.
eeepoint being valve is capable of making this change easily
rocket splash shape /=/ bounding box