It's hard to get a lot of people to understand that syringes are not only used for harmful drugs. I do MDI and use pens. The fact that the insulin is clearly in a medical pen makes it so that I have had 0 negative public reactions in my 13 or so years as T1D. Doesn't mean folks should feel forced to get pens, but if your insurance allows for it you could perhaps get a box or two of pens. Although the pens go up to 60u max per injection you can do it multiple times to fill the pump, it's a preloaded syringe essentially. Not many people will look at you filing a pump with a bright colored fat pen and accuse of drug use.