If Husqvarna says "Run the saw on 50:1 premix", you run the saw on 50:1 premix or richer if you want to use your chainsaw fumes as a cheap and legal alternative to a smoke grenade. As the saying goes never assume to be smarter than the people who designed the saw.
And I am only repeating this once so pay attention. US legislation still allows the use of the terms "synthetic" and "semi-synthetic" which have disappeared in both Europe and Japan due to a massive legal pissing match between Exxon and BP several years back. Lubricants can only be labeled as "synthetic" if the base oil used in them belong to API Group IV (poly-alpha-olefins, PAO for mates) or V (all lubricants not mineral or PAO, usually meaning esters), otherwise they can only be labeled as generic "oil" or "lubricant.
API (which is headquartered in Washington DC) has shrewdly dropped all references to "synthetic" in their documentation and these days only speak about "Group IV" or "Group V" base oils. So in the US "synthetic" is usually nothing more than a marketing ploy.
Many oil merchants (oils are all blended in the same facilities according to the customers' specifications) make wild claims about their products to entice buyers into buying their products. These claims may not be as completely made up as those of fuel and oil additive companies (which landed in serious legal troubles in several European countries) but are 90% advertisement and 10% embellished reality. People believing in these claims will go to incredible lengths to prove themselves smarter than anybody else, like the idiot on another board who kept on pitching an astronomically expensive oil which, according to him, would allow you to run a chainsaw on 110:1 premix (not a typo...
). He claimed to have run his saws for "many hours a day" on that concoction until one of the older guys on the board, possibly after having had a few beers too many, decided to investigate the matter and found he was just some kid with far more money than common sense who fancied himself a big expert on chainsaws and opted for the oil route to dazzle us common peasants while in reality he was barely able to limb a small tree without cutting off one of his own limbs. He had a nice Shindaiwa collection though.
Now if you'll excuse me I need to go and see if a source of scroungeable firewood I have been told about is accessible and I won't break my neck there...