Yeah I went through this whole struggle making qr code generators. It's honestly kind of a nightmare and we should just invent something better:

• phones have different cameras and processing
• you want redundancy in the qr (the data is duplicated) but too much makes the dots too small and quickly toasts reliability
• short urls are everything, because then you can store less data and replicate it a bit more
• even still, various combos of data & phone will refuse a scan and cause support tickets
• people are still quite confused about how you're supposed to scan them, so you have to explain on the card/flyer. Thankfully basically all phone cameras do it by default, but variations in the software don't help, and the ux can differ a bit
• people don't love sketchy links in general, and if the scan is taking too long to aim right, they will give up
• qrs are ugly and changes in color or adding logos quickly causes problems. Qrs don't support logos, people just put em on and use the error correction (as if it's a defect). Lack of spec means logos must be very small

So yeah how about a thing that works and looks good, next time our civilization reinvents bar codes