It's not what I saw on the internet. I went through the time and energy to do these tests myself. When you string three panels together in series you only pass the amperage of the weakest panel. That's not an opinion.
I guess we will will have to agree to disagree. Shade on a panel essentially makes it an unbalanced system as if one of the panels is 150 watts instead of 250. The basics can be found here of solar panels in series vs parallel where unequal panels provide different amperages.
https://solarpanelsvenue.com/mixing-solar-panels/