Agreed. At most we could say that expansion “might” be a mirage. I often wondered, since taking that extremely basic Astronomy 101 class, if the observed red shift in distant light might be explained by something other than expansion.

Of course, I didn’t pursue a career in theoretical physics to sate that curiosity either. So I’m with you in applauding those theoreticians that have “flipped the script” and are exploring alternatives. It can only bolster our understanding. It will either reveal something amazing or rule out dead ends, validating the theories left standing.