Thank you for the detailed responses! I understand.
Makes sense, not a priority - and it probably is better to fallback to the other connection when Shaw does stupid stuff.
Ahh, I had missed that assign button - although oddly enough, even if I assign it, some of the time it doesn't "stick" and I'll see it on ISP DNS servers later... weird. Would using identical DNS servers for both WAN connections screw things up by having conflicting routes during failover, or something like that? Or is that all handled gracefully? I didn't notice any weirdness loading websites - as mentioned, it fails over very quickly. Yank a cable, run back to computer, everything is already loading fine.
I very much appreciate all the work that you've done to enhance the capabilities of Dual-WAN Failover on these routers. You've done a fabulous job!
I just found out that my RT-AX56U on 388.2_2 is EOL as of last month. But I'm happy to use your script as long as I can on this version. Let me know if any testing needs to happen on future betas, to ensure compatibility.