Statistically, you'll find an equal number of products in one 2-hour shift or twelve 10-minute shifts.
Beans are a 60% drop, or a 20% drop doing 10 minutes.
30 minutes: 1/0.6 ≈ 1.667 30-minute shifts to find 1 beans = 50 minutes on average
10 minutes: 1/0.2 ≈ 5 10-minute shifts to find 1 beans = 50 minutes on average
Still, I trust the game more with a 60% drop.
The only thing better about shorter jobs is that your motivation is higher, but the effects are miniscule and the RL time requirements are ridiculous. Do you have premium automation? Do you really want to schedule work every 20 minutes?
In an ideal scenario yes, but I believe 30 minutes will always be better, even when we disregard real live issues.
You get 1 chance at 60%, which is a lot. At 10 minutes you get 3 chances at 20%. Now the catch is, you can't multiply them. It's like rolling a 100-sided dice 3 times. Every time there is 80% chance you will fail, while at 30 minutes there is only 40% chance to fail.
And here comes luck, there is a theoretical possibility you will never get any item. Anyway an item with 60% drop rate will definitely be found, no matter if it's 30 minutes or 10. But if we take a fishing rod with 3% chance and a reduced 1% for every 10 minutes I am quite sure I will choose working longer.