Yes it is vital to have a powerful image and presence when engaging with customers and potential customers. However sometimes style can be the one thing that can attract those new customers to you.
A great way to continue incorporating sneakers and suits is always remember the three foundational rules.
1. Make sure that your shoes are always 100% clean. There's literally no exception here. If you're a white shoe is supposed to be white it should not be brown or beige or off-white because of dirt.
2. Don't wear the gym shoes you work out in with a premium suit or sports jacket and say this is style. It's not. It just does not work. Sneakers worn with suits should be more on a casual Chic side. Or what the British call a smart shoe. The shoe that's not really dressy but also not work out kicks.
3. On that s***. Regardless of how proper or improper wearing sneakers with suits is in the eyes of other people. Who cares. That's something that you want to do and you feel that it will work for you. Do it, and own it. No questions. There are certain people with proper etiquette, or etiquette books, I wrote one by the way LOL, that might say suits should be with leather dresses, etc etc. F**** that. Just make sure to own your style and be YOU.
It's your personality and confidence that will shine more which will allow you to truly gain the clients, the relationships and revenue you desire.