I wasn't impressed with the Amsoil break-in oil and how it mixes (or doesn't mix) with the 4T oil. A couple other builders have expressed similar sentiment.
Even an Amsoil rep. recommended not using the two back to back (that surprised me as well.)
I recommend using only the 4T oil.
If you are not using 4T oil, just be sure to continue to use the same oil throughout the service life of the engine. If you must change brands of oil, then be certain to flush out the crankcase thoroughly.