Steps to reproduce:

1. Open Item configuration
2. Add Preprocessing Step
3. Add user macro to step parameter
4. Press Test one step or Test all steps
5. Result: Macros fields absent in Test form - NOT EXPECTED
6. Go to Item Tab
7. Add user macro to item key parameter
8. Go to Preprocessing Tab and press test
9. Result: All Macros fields present in test form - EXPECTED