Fun perks? Hell no!

Most people don't give because there's no assurance that money will be used properly. It may simply be feeding a habit or going down a bottomless pit.

If a homeless person were raising money not for himself directly but for a reputable charity, then that might motivate contributions. So if the QR code led to a local charity website – one that gives him a place to stay, rehab resources (if needed), counseling, job placement, etc., then someone like me would be much more likely to give.

Where I'm located at the moment, 2 or 3 homeless people per day approach me asking for money. Without assurance that the money would be used to help that person, I don't give. If he held out a QR code that took me to the local charity that's helping him out, that would be entirely different.

He'd become a nonprofit fundraiser rather than a beggar.

And that's a crucial difference – not only for getting results (i.e. money) but also for his self-respect.

Holding out an empty hand = begging.
Holding out a QR code as a fundraiser = employment.