Hello @bleuvert,
The feature to import posts/post contents from third part migration software is currently not available in the WP Travel Plugin.
Also, as importing the contents from the third party plugins will also migrate the post types and taxonomies associated to it, we would require to develop a custom importer functionality to properly accommodate the data in WP Travel plugin.
If you wish to go through the customization approach for your website to get the importer functionality, please send us a customization from the URL below :
http://wptravel.io/hire-wordpress-customizer/
If you have any queries/issues or requests further, please feel free to write back to us.
Best Regards !!