Presumably we are preparing the poem and then put it on the stone, so what would be the danger with Frenzy that isn't fixed by 'don't have a weapon while doing it, keep a calm charge at hand for emergencies' as worstcase preparation?
We go into some kind of... poetic trance, perhaps? Which honestly feels pretty close to overdosing on the mead of poetry, which is connected to Odr...
I don't know, I don't think it's hugely risky, but I'm also fine making the poem whilst lucid instead.