Matt (nprofile…5cc2) I don't see an issue with it because they clearly display SHA256.
Let's take Bitwarden latest release for example. This is a sha for the apk from their GitHub repo (copy/paste)
sha256:fc8c8124650665270925648e0ec35bf7336f26058e3bd72eabf41d859727d220
You will see this same sha displayed in zapstore. Makes no huge difference who signs the release if keys match.