Do NOT use 1.5oz per gallon! That is like 85:1!!! He may have misstyped and meant 1.5oz per tank, which is half a gallon(and still a bit too little IMO but wouldn't cause any immediate damage). 4oz per gallon is fine, and what the manufacturers recommend. 8oz is way too much for a broken in motor, but is how much they recommended to run for the first 2 tanks.
Everyone has their own opinions with oil but I like to lean towards the extra oil side...once broken in I like to use 4.5oz per gallon on these cheap chrome plated motors, which is half an oz more per gallon than recommended. Ends up around 28:1 vs 32:1. I just use a measuring cup with oz on it and eyeball the middle between 4 and 5 for an empty 1gal can.
With the huge tolerances these motors have, the relatively low RPM, and various quality control differences between motors I don't worry much about the quality of the oil and just use whatever cheap synthetic is on sale or available and just use a bit extra. Walmart syntech or w/e works great and is nice and cheap. I'd rather have more of a cheap oil than less or an expensive oil. Has worked great so far on a lot of different motors and they all performed well.
Extra oil within reason won't hurt anything, but too little will. I would never suggest the 75-100:1 that some people run, and personally think 50:1 is not enough oil either. 32:1 is what is recommended by the manufacturer to cover their ass, and IMO a little .5oz extra per gallon is cheap insurance.