The sequel integration doesn't load if you are using the :error_sql extension in your sequel database object.
https://sequel.jeremyevans.net/rdoc-plugins/files/lib/sequel/extensions/error_sql_rb.html
https://github.com/jeremyevans/sequel/blob/master/lib/sequel/extensions/error_sql.rb#L60
There's an issue regarding how this plugin interact with the sequel probe.
One possible solution would be convert or offload the sequel probe functionality into a sequel extension in order to allow manually activating the extension; given that the conflict with the :error_sql extension and Skylight code happens only when they are loaded on a specific order.