I realized that the distances in minecraft golf are a bit smaller than real life. I hit my course today to set up some distance markers 100 yard, 150 yard 200 yard and quickly realized that what looks like a par 4 hole actually measures out to what a par 3 would be. I think that the best thing to do at this point would be have the maximum shot you can take with your driver equal what the maximum distance you can shoot normally. Not only would a distance increase make the arrow despawn before it hit, ( like you found out ) it would force me to complete re-design my course, to take into account the increased distances. Thats the last thing I want to do, since most of my course are already in place and the current design wouldnt allow for me to expand. I say, tone down the velocity to what it was at the beginning, taking the maximum ( non modified ) bow shot as the top end benchmark for the driver and work down from there.