If you want to submit SPL and that too in R4 format as an original submission, it is possible.

It is quite obvious that an applicant may not have all the information required for Structured Product Labeling (SPL) during an original submission. In such a case it is suggested that the SPL submission be done as a part of an eCTD submission, consequently the strict validation rules for SPL R4 would be considered null and void and to the best of our knowledge the submission would not cause any serious consequences.