All revisions (ALPHA/I386/MIPS/PPC) of Windows NT 4.0 and Windows NT 3.51 has issue with maximum possible total video mode count limit and it is around 296 modes. Any mode provided by driver above 296 will be cutted down. It is not depended on driver issue, this bug is inside Windows NT system itself. Windows 2000 and later does not have such issue.
Here it is a binary patch for Windows NT 4.0 (I386, any SP/edition, language) for SYSTEM32\WIN32K.SYS :
Change 0x68 0xB8 0x00 0xFF 0x00 0x00 0x6A to 0x68 0xB8 0x00 0xFF 0x03 0x00 0x6A
Change 0x68 0xB8 0x00 0xFF 0x00 0x00 0xFF to 0x68 0xB8 0x00 0xFF 0x03 0x00 0xFF
Recalculate checksum, f.e. EDITBIN.EXE WIN32K.SYS /RELEASE
Here it is a binary patch for Windows NT 3.51 (I386, any SP/edition, language) for SYSTEM32\WINSRV.DLL :
Change 0x68 0xB8 0x00 0xFF 0x00 0x00 0xA1 to 0x68 0xB8 0x00 0xFF 0x03 0x00 0xA1
Change 0x68 0xB8 0x00 0xFF 0x00 0x00 0xFF to 0x68 0xB8 0x00 0xFF 0x03 0x00 0xFF
Recalculate checksum, f.e. EDITBIN.EXE WINSRV.DLL /RELEASE
This will increase total limit to 1190 modes. Below are results in screenshots, before and after.