I looked at the trigger strip/coil with a timing light, but the ignition seems to advance so fast off idle I could not trust the referance. You would need to trigger a strobe off the pick-up signal. My last job I had exactly what I would need.
Your method is logical and sound. I do however have an '03 spec sheet Kent A sent me from Sweden that states the spec is 1mm BTDC. If I was real ambitious, I could do the same with my 2K-3 that has the insert to fix the timing. What I will do is measure the insert if you like.