The only risk you have when using user-generated content, is that if you use that content, without permission(s) from the owner(s), they can report you to Roblox. As long you have permission and credit then, I see no other reasons why you should be in danger.
This is something i’m also concerned about, but as far as I can tell you shouldn’t get in trouble if the content is not native to your game & is purely user inserted. Of course i’d assume it would depend on individual moderators if they were to see such content within your game - would they ban the user, or your game? There is no clear policy on it, but the moderation failure is on the side of Roblox for allowing such content to be approved, not you as a developer.
Inappropriate decals have become a large issue for me recently, i’ve been logging player’s decal ID’s and reporting them when required but i’ve been noticing disturbing patterns in the way these decals are uploaded & moderated indicating a heavily flawed system of image moderation.
No, I haven’t been moderated for that content but my staff team and I are extremely proactive about immediately banning users of inappropriate decals, logging ALL of their past decal history & reporting every single inappropriate ID accordingly. I applaud for how quick Roblox is to respond to these reports though - the offending assets are usually banned within an hour.
I do expect one day to be moderated for a user utilising an inappropriate decal however, even though it’s ultimately Roblox’s fault and not mine.
(For context, our game has been running for almost 7 years with a decal ID system and we haven’t seen any Roblox moderation over user-content which is great, possibly because we heavily moderate it ourselves.)