I realize that you are asking about the accounts of this matter from people besides Kant, but I would like to respond to the "problem of affection" from the point of view of Kant's own writing. The first thing is that according to the first Critique, the concept of causality is metaphysically interpolated from the if-then relation in pure general logic. Secondly, Kant's thing-talk is not fully split between "things as they appear to us" and "things in themselves" but also includes the phrase "things in general," e.g.:
1. "In the mere conception of a thing in general this is really the case, but not in things as phenomena."
2. "And thus these limitations prove that the representation of an object as a thing in general is not only insufficient, but, without sensuous determination and independently of empirical conditions, self-contradictory; that we must therefore make abstraction of all objects, as in logic, or, admitting them, must think them under conditions of sensuous intuition; that, consequently, the intelligible requires an altogether peculiar intuition, which we do not possess, and in the absence of which it is for us nothing; while, on the other hand phenomena cannot be objects in themselves. For, when I merely think things in general, the difference in their external relations cannot constitute a difference in the things themselves; on the contrary, the former presupposes the latter, and if the conception of one of two things is not internally different from that of the other, I am merely thinking the same thing in different relations."
(Those quotations are from the sort-of-infamous Meiklejohn translation, as available on Wikisource, but so I don't know how much difference other, "better" translations make to the interpretation and application of those passages...) Moreover, Kant sees fit to compartmentalize the first six [edited because I said "eight" originally] categories under the meta-category "mathematical" and the second six under "dynamical," which goes to show that he has a notion with causal overtones that is not quite reducible to the same concept of causation as the category proper is supposed to mark out.
Finally, despite being a noumenal domain par excellence, the moral sphere in Kant has for itself the "categories of freedom" (see also here) yet another interpolation of logical and metaphysical forms.
The "upshot" is that, "A, a thing-in-itself, causes phenomenon B," is not the same kind of statement, despite the wording, as, "A, a phenomenon, causes another phenomenon B." The meaning of "causes" in the first statement is little more than a (trivial!) conditional like, "If a being that is conscious in general is consciously related to a thing in general, then the thing in general appears to the conscious being," which is little more than an overly complicated way of saying that things that can appear can appear. So cause-talk can be mingled with thing-in-general talk a little bit, without there being a full-fledged application of the category of causality proper to things-in-themselves. Or then the little bit of mingling can relate even thing-in-itself talk to cause-talk, without transgressing the strictures of transcendental idealism.
Incidentally, I did find "Kant and double affection: solving the problem", which seems relevant to your actual question. "Kant and the problem of affection" looks like another recent response to the issue.