Hmm, might small bodies of water, say pusdle to pond size, still freeze from the top down because of exposure to colder air and above freezing earth? If the top freezes over all at once it might stay on top unless something breaks it and allows water to flow from under to over
It's still a lot weaker than horizontal. Probably strong enough, but still significantly weaker. Personally i print horizontal without support, cutting bottom face through the head so it lies flat, though that won't work well if you need the head fully intact
Rudy and danger spotted! Who's the 3rd?