Rat trap donut limit?

This is too vague to understand. The most you can get from each truck is three donuts. The amount of level pop ups, offering you donuts, increases as you increase your XP. So, one truck might get you one pop up, or five or more, depending on how much XP you have.

"pigsick57;c-2221291" wrote:
My xp bonus is over 5,000% but however much I increase it, I still only receive around 10 donuts per rat trap truck, which is why I asked whether there is a limit.

In this case you should get 3 rounds (up to 9 donuts) per rtt or more exactly, 3.8 rounds per rtt averaged.

Personally I prefer selling and buying Krusty’s oil rig. My bonus is about 4000% (differs slightly for each of my games) and I get 14 “harps” x 3 = 42 donuts per rig transaction. Saves time and seems more stable than collecting from rat trap trucks.

The Oil Rig is about equal to 5.3 rtt with a base xp of 80000 vs 15000 for one rtt.

All I can tell you is this:
My bonus is 3609.8%. Buying one RTT earns me 1,481,605xp.

My xp bonus is over 5,000% but however much I increase it, I still only receive around 10 donuts per rat trap truck, which is why I asked whether there is a limit.

But you're not receiving donuts for buying a RTT. You're receiving xp. So to get another round of bonuts, you'll have to increase your total xp collected by an additional MILLION points.

Do the math and confirm you're being paid correctly based on the base rate of the RTT multiplied by your 5000%.

Then do the math to determine how much % increase of multiplier = 1M xp for RTTs. THAT is when you'll see more bonuts become available.