I have to admit I am not impressed. My first paper, which I tried to render, does not work properly; references are removed and rendered poorly, figures are misplaced and tables incomplete. Given that not all arXiv papers are under a permissive license and
you do not have permission to do this, I would much prefer if you at least made sure that arxiv-vanity rendered papers do not show up in search results, e.g. by offering a suitable robots.txt and with a bigger link to the author-endorsed version of the paper.
Edit to clarify: If people want to use or develop a broken sort-of-PDF viewer, that’s fine. However, if someone searches for a paper of mine, I would like them to only find the version where I at least had a chance to see that it renders correctly and is complete. In particular, I do not want to be "responsible" for broken rendering on random third-party websites. This website actually operating illegally does not make me more inclined to support it.