Latex is water soluable , Ive always used oil on horizontal surfaces and
never had an issue. Paint or stain on any surface hot or in sun is bad
as products cure to fast and dont penetrate or have time to bond well.
All products carry a sun- hot surface warning , it may not be hot out,
even at 30f dark surfaces get warm, and at 60+ they can be hot. Product
failures are 99% inproper aplication or prep.