I’ve used Belray, and BMW 7 weight oil, in forks that were built using sonic springs for folks, and the lighter weight oil worked well with slightly heavier springs at at oil depth of 125mm compressed, with a preload spacer of 130mm,for the folks who purchase their jeans in the Husky Children’s section at Sears.
However, I’ve been using supertech ATF fluid in all the builds using stock springs, and nobody has complained about in the past 15 years or so.
One thing I have seen OFTEN is how black and nasty the Honda brand fork oil turns between oil changes!
And the bushing are almost always worn off enough to need replacing at each fork oil change.
The ATF fluid never smells that bad, or turns that black, and the bushings still look new between oil changes.
I will continue to use ATF fluid in my forks, and the forks I rebuild for folks, unless they specify something else.
And those that have, often went back to ATF fluid on their next fork oil change.