Also, I have fixed the crash mentioned earlier. The crashed query is about ignoring redundant parentheses under fraction, now it is working:
(6) Ignore redundant parentheses under fraction: https://approach0.me/search/?q=OR%20content%3A%24%5Cleft(1%2B%5Cfrac%7B1%7D%7B(n)%7D%5Cright)%5En%24&p=1