Embedding logo is not a part of the spec, but demonstration that QR codes can be customized. In my experience (and i also have been involved in QR code related

Embedding logo is not a part of the spec, but demonstration that QR codes can be customized. In my experience (and i also have been involved in QR code related startup) these don't take longer to process as long as you don't go over the certain point with customizing the code. It's all about finding the right balance.