Nice to have a builders log , but I wouldn't call it a game changer . It may be required by some DAR's . Properly notated Maint. logs , prop/engine (comp readings) logs , what was done on conditional inspections , operating limitations , etc. are a must . Make sure all the SDR's are done . Then a good fore and aft look at the AC hopefully by someone that knows Thorps ! Remember "It's like a box of chocolates !"
Now I will share with you my experience I had with my builder log for NX115RX . After the AC was signed off by the DAR and all Phase I flying was done , I decided to go to the local FSDO to get my repairman's certificate for the AC . I had at least a 1ft high stack of logs AND a very detailed log with at least 100 photos showing the stages of construction . After I put my stack on the counter the FSDO maintenance inspector only asked to see my California drivers license !! What the farkle !! After 27 years of carefully maintaining records during the build this was all they wanted to see for a repairman's certificate ? I have complete faith in the system ! "Their not happy until I'm not happy !"
RB
I was just venting steam out of various orifices ! 