Dear Jordan Moyers,
Thank you for reaching out.
Unfortunately, forms created directly from a SharePoint List (using the "Forms" button) are bound to the permissions of the SharePoint site and inherit its access controls. Since these forms are designed for internal use within the organization, they do not support external sharing.
Except the workaround that you mentioned there are no easy workaround that we found on our test
We added the user as a guest and shared the list with them, but even though they can create items directly in the list, they cannot access the Forms link.
Thank you for your time and patience, we hope you have a great day!
Kind regards,
Community Moderator | Sophia