I would keep training as if your AeT were ~150 or, better yet, get another lab test if you want to know for sure.
I’m not sure how reliable a race context would be to select training intensities or benchmarks. On the contrary, if AeT was estimated at 149, and you can average 155 in a race, then that sounds about right. My AeT and AnT are about ten beats apart and in a 2-hour skimo race, I usually average right in the middle.
Also, six beats is only a ~3% difference. You’d be splitting hairs to argue 155 versus 149. More importantly, the downside of over-estimating AeT is many times greater than the upside of being super precise about where it actually lies. It will also vary day-to-day, test-to-test.
Using ~150 and getting 97% or more of the benefit is much better than over-estimating AeT, training at too high an intensity, and gradually eroding aerobic capacity.
I hope that helps.