Passing SvelteMap (SvelteSet) from +page.server.ts makes it a normal Map (Set)?

[T1xx1]

Hi, I was wondering if is intended behavoir that passing a SvelteMap or SvelteSet declared from server side in +page.server.ts to a +page.svelte makes it a normal Map (Set) but why TypeScript still tells me that the types of them are SvelteMap (SvelteSet)

+page.server.ts

import { SvelteMap } from 'svelte/reactivity';

import type { PageServerLoad } from './$types';

export const load: PageServerLoad = async () => {
   return {
      sveltemap: new SvelteMap([
         ['one', 1],
         ['two', 2],
      ])
   };
};

+page.svelte

<script lang="ts">
   import { SvelteMap } from 'svelte/reactivity';

   let { data } = $props();

   const { sveltemap } = data;

   console.log('sveltemap from server',sveltemap);

   console.log(
      'sveltemap from client',
      new SvelteMap([
         ['one', 1],
         ['two', 2],
      ]),
   );
</script>

[Ocean-OS]

This question is probably more relevant in the SvelteKit repo, but SvelteKit uses devalue to serialize server-side loaded props, and SvelteMaps and SvelteSets are probably coerced to their nonreactive counterparts during serialization. TypeScript probably has no idea that this happens, so it incorrectly infers the types. Read here for more info.