Imgur now blocks several VPNs and have issues loading embedded previews in several fediverse platforms. So instead of using imgur, you could use one of the following alternatives for uploading your images.
https://postimages.org/
https://imgbox.com/
https://imgbb.com/
https://www.imagebam.com/
As an instance admin I gladly host user files.
One thing to take into account is that images posted by an instanceA user on an instanceB community will still be hosted on instance A.
So as long as an instance doesn’t host more users than it can handle it should be fine.