Grading essay questions when exporting SCORM to Moodle Workplace LMS

I suggest that you make it obvious to the user that there are 2 parts to the assessment, and that passing the auto-Graded question slides doesn't mean they're done. So I'd keep those questions together. Include a Quiz Results slide to score them and to send the score to the LMS) 

Then use Survey question slides for the short-answer/essay questions. You'll need to include the Survey question slides in the Results slide to send the responses to the LMS. 

You'll then have to pull the Survey data from the LMS and have those responses graded manually. How you indicate that the user passed the overall assessment depends on how your LMS works. Since passing a graded quiz = successful completion, it might be best to put the Survey part in a separate SCORM package. Then work with your LMS folks re: the process for marking the item as successfully completed or not.