The way the app works is that it backs up the parameters being changed before the task actually runs. When you revert, it re-uploads those parameters.
So, for example:
1. You run a task to change a price from $100 to $50. The app backs up the $100 price.
2. You modify the price to $20 manually, with another app, or even another task using BPE.
3. You revert the initial task. The app then re-uploads the original parameter of $100.
Therefore, if you run multiple tasks to edits a single parameter, the order in which they are reverted can make a big difference.