The user interface is not very efficient. The user has to manually drag & drop each URL. Other tools whose input are URLs have an easier and speedier approach, like YouTubeTo MP3. The tool for example does not support something as simple as a copy & paste of the url, which would be much faster in many cases.
Beyond this waste of time, the worst problem is that the output is is poorly reflective of web pages! People can have a sense of how mediocre the output can be using the Apple web site (Mac, iMacPro or iPhone sections for example). Pictures are missing. Icons are the top are absent. The length of sections is modified. The resulting PDF takes tons of pages, for a mediocre output!
Given the price of this tool, this is hard to understand (this tool may work for simple, basic layouts).
Given the poor rendering, why not directly print as PDF or save as a web page, which is free and produces a good to great result?