Universal Autofill is slow in Firefox

To preface, this is not a new problem; I’m pretty sure it has been present since I upgraded to 1Password 8 in 2022.

Here’s my grievance: filling in website logins in Firefox via the Universal Autofill hotkey involves an annoying delay, typically between 2–5 seconds depending on the site.

The delay doesn’t occur in Chrome, indicating that Universal Autofill is not inherently slow.

Triggering autofill in Firefox via the browser extension is instant, suggesting that 1P in Firefox is not inherently slow either.

So, what is it about the combination of Universal Autofill and Firefox that induces this delay? Is this a known issue and can something be done about it?