If another code provision already requires backup withholding of a reportable transaction, does the backup withholding provision under IRC 6050W still apply

Yes, the backup withholding provision under IRC 6050W still applies even if another code provision already requires backup withholding of a reportable transaction. The regulations do not eliminate the backup withholding requirements under IRC 6050W under any circumstances, even where the potential for duplicate withholding exists.

Sources:
Publication 1281 (12/2023)
General Instructions for Certain Information Returns (2023)
FS-2023-6
PLR 201539025
T.D. 9496
IRM Part 4. Examining Process. Chapter 23. Employment Tax. Section 8. Determining Employment Tax Liability