Does MailStream Plus support First-Class Mail Incidental or Nonincidental Attachments/Enclosures mailed as part of USPS Marketing Mail

MailStream Plus, all versions, all platforms
There are two types of First-Class Mail Attachments and Enclosures- Incidental and Nonincidental.  In the USPS DMM  (Domestic Mail Manual), the definitions and regulations are in sections 243 2.5.2 and 2.5.3/2.5.4 respectively.  (Current as of August 2019)
Currently, MailStream Plus supports 'Incidental' Attachments and Enclosures, which are ones where there is no additional First-Class postage required.  The postage at the USPS Marketing Mail price for the attachment or enclosure is based on the combined weight of the host piece and the incidental First-Class Mail attachment or enclosure.

The parameter that controls this type of mailing is P ATTR position 68 
UPDATED:  August 28, 2019