Hmm, maybe Da Vinci’s operational time might’ve been shortened by her activities in Fairy Britain? It’s a land for fairies, who never age, so it might’ve been inherently inhospitable for Homunculi, who are inherently short-lived. Drives them to their end faster (on top of spending almost 50 days in there). Dream Upon the Stars seems almost antithetical to Fairy Britain…
Goredolf would know the most about the Homunculi (the Musik family works with them after all), and he seemed especially concerned with Da Vinci joining Gudao and the others, so perhaps he suspected that Fairy Britain might be harmful for her? Would explain why he’s giving it his all to make the Summer Adventure fun for Da Vinci…