Browser lockup when using reactive remote function with LayerChart

[techniq]

Describe the bug

When using a reactive remote function, for example:

const data = $derived(await getData(days));

and trigger a change (days) will cause the browser to freeze/lockup.

This same code works if you switch to client-side synchronous data, for example:

const data = $derived(generate(days));

This was first reported as a LayerChart issue but I'm unable to find any cause and looks like a potential svelte async scheduling issue.

Reproduction

repo (notable this route)

<script>
  import { BarChart } from "layerchart";
  import { getData } from "../data.remote";

  let days = $state(30);

  const data = $derived(await getData(days));
</script>

<h1>remote function (async)</h1>

<button onclick={() => (days = days === 30 ? 90 : 30)}>range: {days}d</button>

<BarChart
  data={data.rows}
  x="day"
  series={[
    { key: "a", color: "tomato" },
    { key: "b", color: "steelblue" },
  ]}
  seriesLayout="stack"
  bandPadding={0.2}
  height={300}
/>

Logs

System Info

svelte `5.56.8` (also tried `5.55.10`)

Severity

blocking an upgrade