If things break, if your hosting environment doesn't allow you, won't fully work, or breaks something on your forum Flarum isn't going to help. It's in beta, and isn't getting much support besides for bug fixes (well support from the community but not mainstream yet). Updates from version to version will be allowed, but if it gets harder and harder (and you loose content, users, posts, etc.) you can't blame Flarum for making their updates not full capability with each other.