I fell ill and there was time to systematize my thoughts about the site. Remember that this is a mechanical translation. I will give them in parts:
Bell Notifications and Inbox
Why it is impossible to update these processes separately and independently from the page of the site !? The implementation of this feature will allow users to respond to alerts in a timely manner.
A lot of people with their specific requests are forced to view the content they do not need while they filter the search. Why not implement filter presets in your profile that you can name as you like and place them in the "grabcad community" drop-down list under the line "community". This will greatly simplify life.
The location of the "Reply" button in the comments. If you write one answer to a comment does not cause problems, then writing a response to a 2-3-N comment causes you to go up to 1 in the list and this is very inconvenient and not logical.
These changes will not only reduce the load on your servers, but also make users happier. ;)