Actually there is no study that proves that aspartame raises insuline levels. Acesulfam-K raised the insulin levels of some rats, but animal studies are outdated and do not say much about what it does to the human body imho. The only study I found about a common artificial sweetener that potentially raises insulin levels was a study about sucralose.
I used to drink softdrinks a lot and still remember I tried avoiding them completely when everybody went apeshit about aspartame. Funny that the products many people bought which were aspartame free (especially bodybuildings supps) probably were more harmful in the end. I remember a lot of protein supps here in germany who were sweetened with sucralose.
I believe that in moderation sweeteners aren't a big risk for us. There are so many bs studies out there, I see them posted daily by my hardcore vegan coworkers fe. I tried to explain to them how studies work. Or the difference between relative and absolute risks of getting diseases like cancer etc. They wouldn't listen. Instead one time a co-worker threw my Milk away because it "offended" him and it was bad for me anyways. Sometimes I really hate working for a hipster company.