Well, Ronan thinks he's better than Muggles (and there's no doubt in his mind about that) but he was only really openly against them as part of the Death Eaters so he could fit in, not that he had a problem with that. Now he really doesn't care whether they live or die, unless them dying is somehow bad for The Ashes/Magical Britain.

Muggleborns he's iffy with, because his own mother was one and raised him to be tolerant, so while he was with the Dark Lord he tried to avoid going to any of their homes, but he is definitely wary of them. He's been told repeatedly that many of them return to their Muggle families after schooling to tell them everything about the magical world so Ronan has a niggling fear that [i]oh god they're going to cause a war that kills all of the witches and wizards they [u]should[/u] be contained[/i]. But he needs them to help The Ashes so he's never going to say something like that, and ones like Jia have earned his respect.