The perennial discussion about ways to provide logged-out users with persistent customization of their reading experience in the browser has cropped up again in the context of the pending deployment of Vector 2022.

Can a cookie-based width toggle be offered without splitting the cache or otherwise making the toggler regret their tog?

The answers currently range from "shouldn't be very complicated or hacky, just toggling a class..." and "can be delivered to logged-out users on top of the cached parser output.."  to "impossible".

Could someone clarify the challenges and costs of trying to toggle css classes in this way?

Warmly, SJ

--