Set `page.data` programatically from `goto()` options while navigating

Describe the problem

SvelteKit currently can preload data on hover and tab. I'm trying to make some routes in my website preload data on viewport too just like preloadCode

Having #12122 implemented would fix my issue, because then i would just be able to preloadData multiple pages at any time and navigating to any of those routes will just happen instantly.
Or even have data-sveltekit-preload-data="viewport" directly.

I tried to make a simple action to kinda solve my problem.
When a link enters the viewport. I preload its data then cache it in memory. but i couldn't find a way to set the page data programatically on navigation, instead of letting sveltekit re-run the server load function.

you can do that with Page.State but not with Page.Data.
so heres my action currently:

import { goto, preloadData } from '$app/navigation';

const cache = new Map<string, Record<string, unknown>>();

async function preloadFromHref(href: string) {
    const result = await preloadData(href);
    if (result.type === 'loaded') {
        cache.set(href.split('?')[0], result.data);
    } else {
        preloadFromHref(result.location);
    }
}

export function preload(node: HTMLAnchorElement) {
    const observer = new IntersectionObserver((entries) => {
        entries.forEach(async (entry) => {
            if (entry.isIntersecting) {
                await preloadFromHref(node.href);
                observer.unobserve(entry.target);
            }
        });
    });

    node.addEventListener('click', async (e) => {
        const cached = cache.get(node.href);
        if (cached) {
            e.preventDefault();
            goto(node.href, {
                // setting the page data programmatically instead of triggering the server load function
                data: cached
            });
        }
    });

    observer.observe(node);

    return {
        update() {
            observer.unobserve(node);
            observer.observe(node);
        },
        destroy() {
            observer.unobserve(node);
        }
    };
}

Describe the proposed solution

Add a data option to goto() that allows setting page data directly, bypassing the load function?

goto(node.href, {
    // changing the page data directly instead of triggering the server load function
    data: cached
});

I already see some problems in types, and making it not break the app if the data is incorrect. but i just though i share the idea.

Alternatives considered

No response

Importance

would make my life easier

Additional Information

No response

Start with the $app/navigation goto() and preloadData() entry points referenced in the issue, along with the supplied preload action. Define how a new goto() data option should interact with navigation and server load behavior; done means cached preloaded data can be supplied during navigation without rerunning the server load function.