There's a Revanced patch for Sync as well as a few other popular apps that let's you continue using 3rd party apps. I'm currently running a patched version of Sync Pro and it still completely works just like it did before.
The current workaround is to become a moderator. Just create your own subreddit and that should potentially give you access to nsfw. Maybe also set the sub to nsfw for good measure.
Here's the guide that I used. I'm also using a modded version of Sync Pro from mobilism, worked just fine in the Revanced patcher and let's you use Pro without crashing.