Opened List not being re-positioned

I noticed the listbox is not positioned well for me, in both Firefox and Chrome. Using the [edgedemo](https://selectlist-polyfill.vercel.app/examples/edgedemos.html) here:

Not colliding with the edge of the viewport and thus not positioning itself above the trigger button. (The black line indicates the end of the window).

Is it supposed to be part of this polyfill to handle positioning? How to support this?

Start by reproducing the issue in the linked edgedemo in Firefox and Chrome, comparing the listbox position with the viewport edge and trigger button. Then inspect the polyfill's positioning behavior to determine whether viewport collision handling is in scope. Done means the expected positioning behavior is defined and the listbox avoids overflowing the viewport when opened.

Written by the indexing model from the issue text.