When you exceed the 2047 character limit for the OEMPnpDriversPath in Sysprep.inf, no error is reported, but the the DevicePath Value Name, a REG_EXPAND_SZ data type, at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion is truncated.
To workaround this limit:
1. Remove the OEMPnpDriversPath from Sysprep.inf.
2. Manually configure the DevicePath Value Name by using Regedt32. Each path should be separated by a semi-colon (;) and should include the %SystemDrive% and %SystemRoot% reference, unlike the relative paths that are used in Syspref.inf.
3. Run Sysprep.
NOTE: Long paths in OEMPnpDriversPath or DevicePath can cause errors during processing.