They would have to be on a fixed (safe) gain basis if so.
That means that roll stability terms might be a bit twitchy in cruise at altitude and thus might have helped contribute to the initial roll PIO. (sheer speculation at this point)
Yeah, they might well be fixed gains, but we don't know if those particular terms are scheduled anyway do we?
OK, it might be a bit less damped in alternate but I suspect that the major change was from stick movement commanding roll rate to stick movement commanding roll acceleration.