Bernardo Kastrup? In the variation of Idealism I lean toward, Unitary Mind
is the ontological primitive, so there can be no 'prior to' that state -- being trans-spatiotemporal there is no point of origin or causation, thus no emergence needed. I'm not quite yet sure what physicalism posits as the ontological primitive, but it surely isn't consciousness, hence having to explain its emergence. So that would seem to be a significant distinction. And doesn't even physicalism have to draw the line somewhere? Otherwise one is left with having to endlessly explain whatever exists, in terms of whatever existed before that, ad infinitum.
As for matter being a problem for Idealism, well that depends on how to interpret the experience of whatever it is one conceives matter to be. Unlike physicalism, Idealism does not consider it to be a mind-independent substance 'out there,' but rather the phenomenal image or appearance of some cognitive emanations/thought forms, akin to Plato's ideas/forms. To me, the problem for Idealism is to explain how Unitary Mind individuates, or 'dissociates' into a multiplicity of finite loci or iterations of mind, to which those 'emanations' come to appear as their experiential, phenomenal content -- such as how it feels to watch an exquisitely beautiful sunset. But whatever Idealism's explanation for that mystery, it seems it would have to be an entirely cognitive event, otherwise what could be the tangible substrate from which any apparently separate form could emanate. Buddhism's take on this seeming dilemma is that emptiness, or formlessness, is not other than form, but that's a whole other metaphysical/spiritual exploration and inquiry into non-duality.