Dave,
Probably the biggest factor is that I knew it would still be fine, and I wanted to take it home with me. The shop where they made it was a 2+ hour trip each way from where I was living at the time, so going back for a non-critical issue would not have been worth it. You are right though- if they did not meet specs, I should have been within my rights to ask for satisfaction. Always wondered if the shop got nervous about the axle position because most trailers that size have the axles much farther back (and thus too much tongue weight for a BB). The trailer under my Broadbill is a factory spec Karavan, and I have often thought about moving the axle forward...
Learned a lot over the years and seasons. There has been some varialbility in CG (especially fishing vs diver duck hunt)of my BB2 while trailering. I developed the initial measurements by putting the boat (empty, but with motor) on my Broadbill trailer and moving it arround to get a reasonable tongue weight, them measuring from the transom to axle. Initially was running a 6 gallon (~50 lbs full??) gas against the forward floatation bulkhead. Now it is against the transom, plus a trolling motor bat on occasion. Occassionally add a couple hundred lbs in dekes and longline anchors that balances who know where. On second thought, the 4" they were off may have been better...can not pull the boat forward to correct for light tongue if the engine lower hits the crossmember. At any rate, I've been happy with how it has worked so far.
Take care!
-Bill