css.properties.object-position - BCD on this doesn't cover support in iframe

What type of issue is this?

Missing compatibility data

What information was incorrect, unhelpful, or incomplete?

Related to https://github.com/mdn/content/issues/32474#issuecomment-2182407633

The property doesn't work on iframes in Chromium-based browsers and Safari. But it does work in Firefox. In the OWD weekly meeting, it was decided that BCD needs to cover the iframe entry for the object-position property.

What browsers does this problem apply to, if applicable?

Chromium (Chrome, Edge 79+, Opera, Samsung Internet), Safari

What did you expect to see?

In the object-fit BCD entry, show iframe is supported in Firefox and not in other browsers.
Or in the iframe BCD entry, show object-fit is supported only in Firefox.

Did you test this? If so, how?

Run the following playground demo in various browsers.
https://developer.mozilla.org/en-US/play?id=M%2BIuRXx6jXT3WN%2FzFjlc5FQ1p%2B8VB0qGSpBnv%2F4B8bTvJRCQtdgRm9Qi%2BaXMV3jGMLkxAnciNkCPtL9a

Can you link to any release notes, bugs, pull requests, or MDN pages related to this?

No response

Do you have anything more you want to share?

No response

MDN URL

https://developer.mozilla.org/en-US/docs/Web/CSS/object-position

MDN metadata

Start with the css.properties.object-position BCD entry and the linked MDN object-position page. Run the provided MDN playground demo in the affected browsers and compare the existing data with Firefox's iframe support. Done means the appropriate BCD entry records iframe support for Firefox and lack of support in Chromium-based browsers and Safari.