Renders are slow when binding to clientWidth or clientHeight inside of keyed-each block

[mhkeller]

Describe the bug

If you have a component that does a bind:clientWidth or bind:clientHeight inside of a keyed-each block, when you re-render, the page will get increasingly slow until it freezes.

This came up here since my library by default binds to clientWidth and clientHeight so it can't easily be used that well inside of keyed each blocks mhkeller/layercake#113

Reproduction

https://svelte.dev/repl/80c226b9830f4dfa8de5e70e7c83f7e0?version=3.55.1

Logs

No response

System Info

REPL, Svelte 3.55.1

Severity

annoyance

[torrfura]

This is probably caused by the multitude of iframes that are being rendered, you can read more here #5524 and here #7583

[baseballyama]

Duplicate of #7583