The FAA recently approved a modification to Experimental Amateur Built Operating Limitations that allow builders to follow a task-based process to flight testing in lieu of simply flying for 40 hours during Phase 1. I spoke to my DAR and he was aware of the change, and plans to issue my operating limitations accordingly. I plan to follow the task based testing approach. I see no downsides to following a careful and considered testing procedure.
FAA’s guidance on the testing procedures is in AC 90-89C Amateur-Built Aircraft and Ultralight Flight Testing Handbook.
You can also get the EAA’s Flight Test Manual and Test Cards.