I am confused, are you for or against FOUC? Or for optimizing against it?
My core industry is e-commerce, have been doing it for over a decade. Our fastest sites are the fully cached, single CSS file sites. You get sent a small amount of CSS and HTML, and you are off to the races. Javascript comes later, and is not necessary to operate the site until checkout.
What kills a sites speed for us is usually shitty CDNs and bloated assets, we don't have those. There isn't a single e-commerce platform popular today that I feel does this well, but that is because they are all enterprise platforms full of enterprise features.
My core industry is e-commerce, have been doing it for over a decade. Our fastest sites are the fully cached, single CSS file sites. You get sent a small amount of CSS and HTML, and you are off to the races. Javascript comes later, and is not necessary to operate the site until checkout.
What kills a sites speed for us is usually shitty CDNs and bloated assets, we don't have those. There isn't a single e-commerce platform popular today that I feel does this well, but that is because they are all enterprise platforms full of enterprise features.