[lnl]

I would hope that Firefox would have an about:config setting to disable it, but with the direction they are going, removing customizability left and right, who knows. Normally I would have also expected addons to disable this browser-side lazy loading, but since Firefox 57 they are more like glorified userscripts, so they probably wouldn't be able to.

On Chromium side, maybe Vivaldi and the like could provide the option to disable it, if it is not too difficult of a change on Chromium. But for sure, I would be very surprised if Chrome offered that option, so not much of an improvement for Chrome users, or maybe even a deterioration if sites start to adopt it even more, now that it is supported natively.

[bzbarsky]

Firefox does not have plans to implement lazy loading at this time, fwiw. If we do, yes, I expect we will have a way to disable it.