I wanted to retain the look and feel of the modern SharePoint list new/edit form but auto populate a field with current logged-in user. I don't want to use the Power apps form as it will require me to change/create all fields and set their properties(as far as I am aware).
Is there a way around to change the behavior of just one field in Power apps plus retain SharePoint list form?
Please note that I wanted to use some JavaScript but modern SharePoint does not allow it.
SharePoint online does not provide any out of the box way to specify a default/auto populated value for Person column type.
If user is not going to modify the field after auto-populate, you can consider using Created By/Modified By field for your requirements.
The Created By field is auto populated with the current user when adding a new item while Modified By field is auto populated when editing a new item.
If you want to auto populate the value & allow editing of field, you have to customize the list form using Power Apps. In this case, you have to customize the entire form as there is no way to change the behavior of just one field in Power apps & retain out of the box SharePoint list form.
