There are many threads where people keep discussing how WUs work, people share tips, people debunk those tips etc. For some things there are no answers really, even with Support team or documentation.
Here are some examples:
- Searches - When do they run? How do we optimise them?
- Bubble is definitely overcharging us for WUs
- WU cost for Exporting and Importing database
- Lowest WUs on Pagination Functions
- Transparency in WU Charges: Let’s Unite for More Clarity!
- WU bugs - overcharged
- Search: count is 0? Or Search:first item is empty?
- Security Risk with Recommended Data Rules! - #32 by mghatiya
And this is after I am not that active on forums. I am sure there are many such posts which highlight how things are genuinely unclear when it comes to WUs.
I think current documentation is a good start, but there is a lot of ground to be covered to make WU calculation and optimisation clearer to people.