I didn’t see this question when you initially posted it, sorry! You’ve possibly been following the Gargoyle Unicode discussion here, and the quick answer is yes, this isn’t foolproof, as Gargoyle just lies and says it can print anything.
As noted in that other discussion, though, I’ve been working on font substitutions, which should largely alleviate this problem. With the current test code I’ve got, the illuminated scroll you mentioned now looks like this:
