I don't think anything I said implied that Ukraine was morally unimpeachable on the military side. If we were talking about whether or not Ukraine should be able to torture Russian POWs or impersonate medics or firebomb Russian apartment complexes then this would be a very different conversation and I would be saying very different things. I also don't think anyone is saying that use of cluster munitions is a good thing, only that it's the lesser of all available evils.
I do think that under all circumstances it's very unhelpful and even paternalistic for us to tell Ukraine what they can and can't do for their own good. Ukraine is not fighting the Iraq war or Vietnam here. They're not lunatics, they're not children, and they're not fighting because they've been lied or manipulated or bullied into it by their leadership. They're fighting a defensive war of annihiliation in which they either win or die, much of the civilian population included. Given that, they are the only ones who should be allowed a say on what risks they are prepared to take and what costs they consider acceptable, and our role in this should be to shut up and help them unless they are genuinely violating international law. There might one day come a time where the Ukrainian people start disagreeing with the Ukrainian leadership on how far to go, and if that ever happens then I'm happy to weigh in on the side of the people, but we're not there yet - last I heard Zelenskiy was still incredibly popular.
I also didn't say there was "no downside" to using cluster munitions more. I would instead say that most of the downside is already there thanks to Russia's extensive use of them. Obviously the more bombs are present the more likely it is that someone is killed, but AFAICT the deaths are not the worst part of unexploded munitions because they are typically rare. The problem is that the reason deaths are rare is that the instant the immediate threat is over, the government has to designate huge swathes of the country as de facto minefields, unsafe for everyone including the people who used to live there until they can be painstakingly cleared. Even afterwards, the risk is never entirely gone and the population has to live with that - people don't feel safe walking in the countryside they grew up in for decades after the fact. That, to me, would be the worst part, and past a certain point increasing the number of munitions used in a given engagement makes very little difference to it.
This is absolutely a real and important effect, but we should bear in mind that this poll isn't the thing proving it so it's kind of a bad headline. In particular, the headline suggests that this is a new and tentative finding rather than something that's been known for ages, and that it's possible to disprove the effect by knocking down this survey. Intergroup contact theory actually goes back to the 50s and AFAICT is incredibly well-established.
To prove the effect exists with a survey like this, you would need to carefully disentangle the people who "don't know any trans people" because they don't know any trans people from the people who "don't know any trans people" because all the trans people in their life are terrified of coming out to them. Conversely, you would need to carefully disentangle the people who "know a trans person" because they know someone who's out to the world from the people who "know a trans person" because they know someone who's out to only a very few people who they already had good reason to believe would be supportive. There are ways of doing this for people who are better at statistics and experiment design than me, and as I understand it there are studies which do it carefully and do prove the effect, but this isn't one of them and doesn't try to be. (And why should it try to be, when the effect's existence has already been established and studied separately, and when the raw data on a large current sample is useful without reinventing the wheel?)