Sunny,
In respect of your Zenith project, you are overthinking the exercise. One of my students has just completed his Z750 under guidance from his local Technical Counsellor, (SAAA). It was signed off into VH rego by our local Authorised Person, (AP), and we've flown off the Phase 1 test flying without any hitches. With Phase 1 completed, it has been signed off again by local AP and student is about to continue his training in it. There were no delays, hitches, purges, whatever from the regulator, because they appoint an AP to do this work. The APs do a good job, and good test pilots achieve the levels of safety the regulator expects from us. Don't throw away your project - enjoy the flexibility and freedom that those before you have battled long and hard for.
happy days,