I had many issues with Sales Commission moudle as well. Beside many bugs, it lacks flexibility also. We should fix this on priority, once we start adding more features:
1. If Sales Person sells [invoice] more than say X dollars, he should get commission Y*Z and not Y*Z-X as currently. Where Z is the total sale he did. Means I want to geneate commission on total sale when it crosses certain limit but don't want to subtract any amount.
2. This is for Collection Commission [Reciept]. I want to give commission if Sales person can collect the payment within one month of sale [invoice].
3. The Exclusion Clause - Means generate Commission for all BP/Product Groups/Product EXCEPT for the select one. This will save us from creating many rules.
4. Another thing is that is it should be lot easier if we can generate Commission for all the Sales Persons in one Run, but need to be separately invoiced.