I have a 2014 KIA Rio (Same as an Accent.) I have used Full syn mostly, with an occasional Semi-Syn. As some have posted, keep it to full mark. The issue with these GDI engines is fuel dilution, so that's really why I run Full Syn most of the time. Usually about every 5K. Brand doesn't matter in these engines. I use whatever is on sale or I have gotten a great deal on in bulk. 5W-20 or 5W-30, where I am, doesn't make a difference. I have used Supertech, QS, Havoline ( a lot of this as I got it for $7.99/5 qt container---bought about 13!) and NAPA. No difference whatsoever that I could see. Approaching 100K, no issues. Car runs fine.
Bottom line in reality? Doesn't matter what you use.