Yes, PNCC Proposals should be included in NIH Other Support and NIH Biosketches for grant application as of January 25th, 2022. PNCC does not provide support letters. However, PIs can describe the process to apply for a PNCC Proposal in applications at the facilities/equipment section of grant applications, if desired.
Please use these resources for more information:
https://grants.nih.gov/grants/guide/notice-files/NOT-OD-21-122.html
https://grants.nih.gov/grants/forms/othersupport.htm
https://grants.nih.gov/grants/forms/biosketch.htm