RKWard has been available for Windows for many years, now, and for all I am aware is in fairly good shape on that platform. With RKWard 0.7.3, released earlier today, we now also have a reasonably recent offering again.

Note that we'll switch to building against R 4.2 in maybe a week or so, once we're confident that no urgent fix is needed. Not sure, whether it makes sense to start a submission before that time.