One setting for every device means the choice that suits desktop also applies where it doesn't. Mobile visitors are on slower connections, tighter data and a different browser mix. They rarely want the same configuration.
What changed
Open Navigation AI’s settings from the @NavigationAI mention in its instructions and every control now has a device icon beside it. Click it and the single setting splits into two, desktop and mobile, each set independently. Leave it alone and one value covers both, as before.
Three things can be split this way. Optimization mode, so you can run Max on desktop where headroom is cheap and Eco on mobile where it isn’t. Custom excludes, so a path you skip on mobile can still be optimized on desktop. And Safari prefetch, which is the one worth understanding: it prefetches using fetch() on Safari, and turning it off avoids uncached requests on sites without Cache-Control headers. If your desktop and mobile traffic hit different caching setups, that’s now two decisions instead of one compromise.
Worth knowing that these are your starting instructions, not locks. The agent may adjust them in pursuit of its goals, and the modal says so.
- Split any setting by device, or leave it as one value for both.
- Eco on mobile, Max on desktop, if that’s the trade-off you want.
- Safari prefetch per device, for sites where caching differs between them.
- Your settings guide the agent, which may still tune them toward its goals.