While the short link generation is the best at short.io, The QR Code generation, whether through the dashboard or through API is very basic wherein we can only choose the color of the QR Code and the background. I would suggest to have more options for QR code styles wherein the eye style could be round, rounded, etc, eye color could be changed, and so much more in terms of the QR code Styling.
If this is done, I would say that short.io would be by far the best service out there as i have compared and tried almost all services out there. Short.io has more options in terms of shorturl generation, both with dashboard as well as api. Only missing feature is styled QR codes.
I hope you will look into my request ad prioritize the QR styling feature, both through dashboard as well as through api.