If you need to remove default option on additional purchase, you will need to create a dummy additional purchase item to move the default option onto it and remove it afterward, see steps below:
  1. Log in to ACTIVEWorks Endurance with Existing ACTIVE Passport Account > choose event > Event setup > proceed to Additional Purchases
  2. Click Edit 
  3. Click pencil icon User-added imageof desired product
  4. Click Add to create a new item
  5. Fill in item information and make sure no Availability is selected
User-added image
  1. Click Apply 
  2. Check Default for the new item you just created
  3. Check the box in front of new item 
  4. Click Delete
User-added image