WP 4.9 support

Thank you for a nice plugin. Good work!

Despite plugin says, it requires WP 5, seems, that it still works with WP 4.9 and ClassicPress, at the same time. So, I’m asking to leave the support of WP 4.9, because our clients are not willing to migrate to Gutenberg, but still want to use your plugin.

Thank you for your efforts!