Hi, and thanks for the original tutorial! I have looked into this again recently at the request of a fellow redditor and ended up looking for different hardware. I found this:
GL.iNet GL-MT300N-V2
and it looks really intriguing. Ignoring the vile colour it seems to have everything the WT3020F does except OpenWRT is preinstalled. Would you agree it's a good option if you were doing this from scratch? I think it would save headaches myself