TYPO3 replacement for "top margin" and "bottom margin" in LTS 7

With TYPO3 LTS 7 and up, top margin and bottom margin are not suported by Fluid styled content.

css styles content

My users used a lot of those margins in 6.2 LTS

How can I do to make this working again (override TCA, extension, etc)?

I think you can

1. install Fluid Styled Content and CSS Styled Content;
2. then don't add the static typoscript of css styled content.
3. modify the templates or partials of the Fluid Styled Content elements to use the new fields.

I don't know if this scenario has hidden drawbacks that I currently don't see.

Another scenario could be to use the CSS Styled Content also on version 7 and plan a migration to version 8 or 9 where they're used again, but the fields have become dropdown lists; plus, even the field names in database have changed: in version 6.2 they were spaceBefore and spaceAfter while since 8.7 they're called space_before_class and space_after_class.

As far as I know there are no conversion or upgrade tools between these fields.

See here and here for further details.