This board (among several others) will without a doubt die a slow death if the admin doesn't implement a better solution. Disabling hotlinking not just to images but entire boards is not a "minor hurdle" but a major one.
8moe I believe has the same host as Gelbooru. Here's how they work around this same issue: by having people toggle on an option to see the content (without having to sign in to an account) which saves a cookie to bypass the block.
https://gelbooru.com/index.php?page=account&s=options
I think you can do even simpler than what Gelbooru does (where they have people go to a separate page to flip a toggle) while still maintaining the "minor hurdle" definition. I propose for the "contentious boards" disabling hotlinking to all images as they are right now, re-enabling hotlinking to these boards, and changing the way thumbnailing works such that there are two sets of thumbnails: blurred or mosaic pixelated thumbnails (whichever algorithm is faster, don't remember) and normal thumbnails. For all users by default they see the blurred/pixelated thumbnails. When a user clicks a thumbnail a dialogue box should appear stating that contentious content is blocked by default and asking if the user would like to enable it by flipping a toggle. After the user flips on the toggle, a cookie is saved with this information, he can see the normal thumbnails and full images and visiting hotlinks to these images is also enabled. Or in other words, it's like having an account on Sad Panda / Sankaku, but using Gelbooru's approach of using a cookie instead of an account.
Ask the admin about this. If the admin refuses to simplify this hurdle I suggest finding a new home for /rule34/, maybe talk to the other board owners like
>>>/loli/ ,
>>>/ss/ and so on about it too. I would suggest banding together and chipping in to hosting your own imageboard for these boards (and also ask for BTC donations on this new site to help cover hosting) with the same web host. Use vichan instead of Lynxchan, the first one is very easy to code in custom features from my experience, the latter is extremely overengineered and difficult to add new features like the above I mentioned. If you folks go ahead with this idea and need help with server/site administration, general PHP/vichan development, caching, security, etc. let me know.