I see what you are indicating at the bottom of that depression but I really don't know what to make of it. I wish we could send someone to investigate that little trench in person.
Yes
Message 272 has the same sort of image of small clasts stuck in and suspended in the sandstone. They are not "boulders," the setting is exactly the same as for the small clasts we've been discussing, even with that little ridge you called a bedding plane. On such a tiny scale I don't see how you could draw such a conclusion from it as "It also indicates that there was erosion of the igneous/metamorphic rocks during deposition of the Tapeats."