I cannot update these fields as an activity is created in the automation. I would like to automatically invite the person who is related to the activity to the guest field for certain appointment types. I know these are newer fields but hope to see them being able to get automated soon. Also, if the activity being created is linked to a person, then the person's email and location should be a one click add to the location and guest fields as it only makes sense that you would want to go to their location or you would like to send them a calendar invite.. I believe I did see that option on the guest field a few weeks ago but it no longer does that in the guest field.