Block/inline setting not working
Embedded blocks displayed as inline elements in CKEditor, but render as block elements.
Issues
Additional attributes get stripped
iframe attributes not provided by the module get stripped.
Many embed codes include extra attributes, so this module can't be...
Allow creating and embedding non-reusable Custom-Block [BlockContent] Entities
Allow reusable blocks for entity embed.
Modules
Iframe
Iframe field.
CKEditor iFrame
Embed iframes in CKEditor.
Media Embeddable
Create HTML/iFrame/Javascript snippets as reusable media items.
If you want a better iframe config form, try Media Entity Inline Frame.
Embedded Content
Themable embedded content.
Similar to CKEditor 5 Template, but has an edit form and changes to display can be made in code.
Simple oEmbed
oEmbed urls in formatted text.