If you want to connect several usb devices and maintain a clean looking front on the console you should get an otg hub.

Something like this https://www.amazon.com/dp/B07VVNNQ8Q

You can plug an OTG microUSB hub into the back of your hacked snes mini to use USB controllers like https://www.amazon.com/SUYAMA-Adapter-All-New-Nintendo-Playstation/dp/B07VVNNQ8Q and plug your power microUSB into the other end.

Some games (Eg NES gauntlet 2) just detect all controllers and you don’t have to do anything extra

Instead of using a usb hub, use a otg hub like this one

https://www.amazon.com/SUYAMA-Adapter-All-New-Nintendo-Playstation/dp/B07VVNNQ8Q

And make sure to use a decent power adapter, with at least 5V 2A output.

I'd also say, if you can still return it, go for an OTG adapter. Currently recommended as far as I can see is this https://www.amazon.com/SUYAMA-Adapter-All-New-Nintendo-Playstation/dp/B07VVNNQ8Q. Cheaper and looks cleaner when the front ports are free IMO.

The OTG hub I use is, unfortunately, no longer compatible with the NES and SNES Classic if you buy the current model. However, this one seems to come recommended by several people these days.

No soldering is needed to use an OTG with these hubs. They plug into the power port of your system. hakchi CE is already set up so it can be used with USB drives; you just plug your USB drive directly into your PC, not the OTG device, then use hakchi's "export to USB" button instead of synchronize. Then you plug it back into your OTG and connect it to your system.

I personally don't recommend the L-shaped OTG adapter recommended by others because I had bad experiences with it, but your mileage may vary.

https://www.amazon.com/SUYAMA-Adapter-All-New-Nintendo-Playstation/dp/B07VVNNQ8Q

This is what they recommend at their discord. Looks solid, I'd go with that