I've been trying a Pixel 4a with no success using the stock dual wan fail over functionality. Looking to try again with @Ranger802004's script this weekend. Hopefully I will have better results to share.
Great, I also have a Pixel4a. I'm looking forward for your experience, even though I believe here the issue is that the phone doesn't get detected at all, and in fact @m33ts4k0zsaid he tested the script with no success.
No sorry, I mean using the standard functionality available through the Merlin firmware, which I'm considering to probably come close to what stock Asus firmware would give you. I have not tried using it as the primary wan, and quite frankly, not sure if that's even possible.