I like the danger of potentially losing what I mine; it keeps life interesting. No reason to add this in my opinion, and this is coming from the laziest person on this planet... -1
This is potato math which doesn't take into account much at all. First off the current fastest type of pumpkin farming is going 2 lanes at a time alternating A and D at around speed 5. This is the fastest reliable method I have tried many believe me. However, were the problem of picking up pumpkins be removed the fastest method would switch to the one where you stand on the stalks and clear both at once at a much faster speed. Not only is this method much faster your math is also faulty because you don't pick up a row every sixty seconds and if you did it would take much longer to pick them up as there would be multiple rows. Every 2 wide row takes about 10-12 seconds to pickup cause pumpkins are a pain in the ass and you still cant go over them fast when picking them up or they wont go into your inventory. This is 10-12 seconds AFTER clearing a row which only takes like 15-20 seconds. This is like a 70% increase in efficiency. Add this to the fact we can now use a different method and pumpkin farming will likely clear double profits.
How many pumpkins do you get from a full row of pumpkins on a 200x200 farm? I would test it but I can't atm.