[Bierp]

That nut has to be 1.5" or more in diameter. I don't think a basin wrench can cover that. (Am I wrong?)

I have a tool similar to this, which has served me well on faucets in the past, but it's also too small to get over the threaded tube or the nut. https://www.amazon.com/Installer-Mul.../dp/B08XBLSM6G

I wonder if I could get one of these around it though? https://www.lowes.com/pd/Kobalt-Adju...nch/1002645196

That was shown as a specialty tool from your basin wrench link, so if that does the trick, you get full credit.