I guess I'm missing the point that it is a cruiser with bars that make a rider ride with their arms raised making their shoulders lift. Then there is the glasses thing which I also missed.
I would venture to say you need to decide just how much you are willing to trade off in "inconvenience" to yourself for safety. If you want to maximize protection, you do a full face and do whatever it takes to see. If you aren't willing to do what is necessary you decide where you hit the limit. No helmet no inconvenience.
Having ridden wearing a full face since 1975 and with glasses full time since around 1995 I deal with whatever is needed. I don't even notice it.
everything is automatic. Glasses off to put on or take off a helmet - no problem - automatic. Turning however necessary to see in my blind spot a bit of problem onlly due to the three fused cervical vertebrae, not the helmet. I turn at the shoulders and waist as needed, depending on the situation.
I do make sure my mirrors (both sides all the time) actuallly enable me to see behind and as best possible to the sides of me. I will lean forward or lean slightly to see what is close behind as well as turning to look.
To put it mildly, I wear the best head protection (brain injuries, like eye injuries don't heal well), I do whatever is needed to see what is behind me and in blind spots. I actually do worse with the blind spots in the car.
KLX650C, Zephyr 550
SR500, Bultaco Sherpa T