Ohhhh okay @tahnalos,

Thanks for the screenshot, you're right. I tested it on a PDI, and the Omit insert row condition didn't hide the row, either as admin or as a regular user.

What did work was showing that list as a related list instead of an embedded list:

1. Remove the embedded list from the form (Configure > Form Layout).
2. Add it back as a related list (Configure > Related Lists).
3. Right-click the related list header > Configure > List Control, check Omit new button and Omit edit button, and leave List edit insert row unchecked.

Users still see the records on the form but can't add new ones from there. And since the create ACL doesn't change, they can keep creating them the usual way.
before

Now