UPDATE:
I finally had the opportunity to get back to work on this. I popped off both welch plugs and, probed all passageways and did (another) thorough cleaning in the ultrasonic.- Same results with the starting and low and high settings as my original post. Once it has started and warmed up the engine idles and runs very good. Should I still be concerned for any reason? My feeling is to let it go and move on to the next project...
Michael