I have the Realforce 23U and just tested it with EK's Switch Hitter and it sends the correct codes. They are as follows:
Keys 0 - 9...
14:41.0138 Num Lock (0x90, BIOS 0x45) DOWN
14:41.0138 Num Lock (0x90, BIOS 0x45) UP -> 8ms
14:41.0138 0 (0x60, BIOS 0x52) DOWN
14:41.0241 0 (0x60, BIOS 0x52) UP -> 95ms
14:41.0241 Num Lock (0x90, BIOS 0x45) DOWN
14:41.0257 Num Lock (0x90, BIOS 0x45) UP -> 8ms
14:41.0602 Num Lock (0x90, BIOS 0x45) DOWN
14:41.0618 Num Lock (0x90, BIOS 0x45) UP -> 16ms
14:41.0618 1 (0x61, BIOS 0x4F) DOWN
14:41.0722 1 (0x61, BIOS 0x4F) UP -> 103ms
14:41.0722 Num Lock (0x90, BIOS 0x45) DOWN
14:41.0738 Num Lock (0x90, BIOS 0x45) UP -> 8ms
14:41.0847 Num Lock (0x90, BIOS 0x45) DOWN
14:41.0863 Num Lock (0x90, BIOS 0x45) UP -> 16ms
14:41.0863 2 (0x62, BIOS 0x50) DOWN
14:41.0957 2 (0x62, BIOS 0x50) UP -> 103ms
14:41.0978 Num Lock (0x90, BIOS 0x45) DOWN
14:41.0978 Num Lock (0x90, BIOS 0x45) UP -> 8ms
14:42.0090 Num Lock (0x90, BIOS 0x45) DOWN
14:42.0102 Num Lock (0x90, BIOS 0x45) UP -> 16ms
14:42.0102 3 (0x63, BIOS 0x51) DOWN
14:42.0149 3 (0x63, BIOS 0x51) UP -> 47ms
14:42.0149 Num Lock (0x90, BIOS 0x45) DOWN
14:42.0165 Num Lock (0x90, BIOS 0x45) UP -> 8ms
14:42.0322 Num Lock (0x90, BIOS 0x45) DOWN
14:42.0322 Num Lock (0x90, BIOS 0x45) UP -> 8ms
14:42.0322 Num 4 (0x64, BIOS 0x4B) DOWN
14:42.0398 Num 4 (0x64, BIOS 0x4B) UP -> 79ms
14:42.0418 Num Lock (0x90, BIOS 0x45) DOWN
14:42.0418 Num Lock (0x90, BIOS 0x45) UP -> 8ms
14:42.0574 Num Lock (0x90, BIOS 0x45) DOWN
14:42.0574 Num Lock (0x90, BIOS 0x45) UP -> 8ms
14:42.0574 Num 5 (0x65, BIOS 0x4C) DOWN
14:42.0652 Num 5 (0x65, BIOS 0x4C) UP -> 71ms
14:42.0652 Num Lock (0x90, BIOS 0x45) DOWN
14:42.0668 Num Lock (0x90, BIOS 0x45) UP -> 8ms
14:42.0792 Num Lock (0x90, BIOS 0x45) DOWN
14:42.0807 Num Lock (0x90, BIOS 0x45) UP -> 16ms
14:42.0807 Num 6 (0x66, BIOS 0x4D) DOWN
14:42.0854 Num 6 (0x66, BIOS 0x4D) UP -> 55ms
14:42.0870 Num Lock (0x90, BIOS 0x45) DOWN
14:42.0870 Num Lock (0x90, BIOS 0x45) UP -> 8ms
14:43.0072 Num Lock (0x90, BIOS 0x45) DOWN
14:43.0072 Num Lock (0x90, BIOS 0x45) UP -> 8ms
14:43.0072 Num 7 (0x67, BIOS 0x47) DOWN
14:43.0170 Num 7 (0x67, BIOS 0x47) UP -> 87ms
14:43.0178 Num Lock (0x90, BIOS 0x45) DOWN
14:43.0186 Num Lock (0x90, BIOS 0x45) UP -> 8ms
14:43.0320 Num Lock (0x90, BIOS 0x45) DOWN
14:43.0320 Num Lock (0x90, BIOS 0x45) UP -> 8ms
14:43.0320 Num 8 (0x68, BIOS 0x48) DOWN
14:43.0398 Num 8 (0x68, BIOS 0x48) UP -> 71ms
14:43.0398 Num Lock (0x90, BIOS 0x45) DOWN
14:43.0418 Num Lock (0x90, BIOS 0x45) UP -> 8ms
14:43.0543 Num Lock (0x90, BIOS 0x45) DOWN
14:43.0559 Num Lock (0x90, BIOS 0x45) UP -> 16ms
14:43.0559 Num 9 (0x69, BIOS 0x49) DOWN
14:43.0606 Num 9 (0x69, BIOS 0x49) UP -> 47ms
Non-number keys in this order: . Enter + - * \
- 14:43.0621 Num Lock (0x90, BIOS 0x45) DOWN
14:43.0621 Num Lock (0x90, BIOS 0x45) UP -> 8ms
15:11.0831 Tab (0x09, BIOS 0x0F) UP -> 34238ms
15:11.0831 LShift (0x10, BIOS 0x2A) UP -> 34249ms
15:11.0831 RShift (0x10, BIOS 0x36) UP -> 34250ms
15:11.0831 LCtrl (0x11, BIOS 0x1D) UP -> 34251ms
15:11.0831 RCtrl (0x11, BIOS 0xE01D) UP -> 34251ms
15:11.0831 Tab (0x09, BIOS 0x0F) UP -> 9ms
15:11.0831 LAlt (0x12, BIOS 0x38) UP -> 34253ms
15:11.0831 Tab (0x09, BIOS 0x0F) UP -> 4ms
15:11.0831 RAlt (0x12, BIOS 0xE038) UP -> 34253ms
15:11.0847 Tab (0x09, BIOS 0x0F) UP -> 3ms
15:11.0847 Tab (0x09, BIOS 0x0F) UP -> 2ms
15:11.0847 LShift (0x10, BIOS 0x2A) UP -> 17ms
15:11.0847 RShift (0x10, BIOS 0x36) UP -> 18ms
15:11.0847 LCtrl (0x11, BIOS 0x1D) UP -> 20ms
15:11.0865 RCtrl (0x11, BIOS 0xE01D) UP -> 29ms
15:11.0871 Tab (0x09, BIOS 0x0F) UP -> 23ms
15:11.0871 LAlt (0x12, BIOS 0x38) UP -> 31ms
15:11.0871 Tab (0x09, BIOS 0x0F) UP -> 13ms
15:11.0887 RAlt (0x12, BIOS 0xE038) UP -> 42ms
15:11.0887 Tab (0x09, BIOS 0x0F) UP -> 3ms
15:11.0995 Tab (0x09, BIOS 0x0F) UP -> 122ms
15:12.0011 LShift (0x10, BIOS 0x2A) UP -> 161ms
15:12.0011 RShift (0x10, BIOS 0x36) UP -> 159ms
15:12.0011 LCtrl (0x11, BIOS 0x1D) UP -> 156ms
15:12.0011 RCtrl (0x11, BIOS 0xE01D) UP -> 147ms
15:12.0011 Tab (0x09, BIOS 0x0F) UP -> 5ms
15:12.0011 LAlt (0x12, BIOS 0x38) UP -> 143ms
15:12.0011 Tab (0x09, BIOS 0x0F) UP -> 2ms
15:12.0011 RAlt (0x12, BIOS 0xE038) UP -> 131ms
15:12.0011 Tab (0x09, BIOS 0x0F) UP -> 2ms
20:14.0627 Tab (0x09, BIOS 0x0F) UP -> 302613ms
20:14.0627 LShift (0x10, BIOS 0x2A) UP -> 302622ms
20:14.0627 RShift (0x10, BIOS 0x36) UP -> 302622ms
20:14.0627 LCtrl (0x11, BIOS 0x1D) UP -> 302622ms
20:14.0627 RCtrl (0x11, BIOS 0xE01D) UP -> 302622ms
20:14.0627 Tab (0x09, BIOS 0x0F) UP -> 5ms
20:14.0627 LAlt (0x12, BIOS 0x38) UP -> 302622ms
20:14.0627 Tab (0x09, BIOS 0x0F) UP -> 2ms
20:14.0642 RAlt (0x12, BIOS 0xE038) UP -> 302624ms
20:14.0642 Tab (0x09, BIOS 0x0F) UP -> 7ms
20:14.0642 Tab (0x09, BIOS 0x0F) UP -> 3ms
20:14.0642 LShift (0x10, BIOS 0x2A) UP -> 18ms
20:14.0642 RShift (0x10, BIOS 0x36) UP -> 18ms
20:14.0642 LCtrl (0x11, BIOS 0x1D) UP -> 18ms
20:14.0642 RCtrl (0x11, BIOS 0xE01D) UP -> 18ms
20:14.0658 Tab (0x09, BIOS 0x0F) UP -> 9ms
20:14.0658 LAlt (0x12, BIOS 0x38) UP -> 21ms
20:14.0658 Tab (0x09, BIOS 0x0F) UP -> 2ms
20:14.0658 RAlt (0x12, BIOS 0xE038) UP -> 19ms
20:14.0658 Tab (0x09, BIOS 0x0F) UP -> 2ms
20:14.0767 Tab (0x09, BIOS 0x0F) UP -> 118ms
20:14.0767 LShift (0x10, BIOS 0x2A) UP -> 130ms
20:14.0767 RShift (0x10, BIOS 0x36) UP -> 130ms
20:14.0783 LCtrl (0x11, BIOS 0x1D) UP -> 130ms
20:14.0783 RCtrl (0x11, BIOS 0xE01D) UP -> 130ms
20:14.0783 Tab (0x09, BIOS 0x0F) UP -> 5ms
20:14.0783 LAlt (0x12, BIOS 0x38) UP -> 127ms
20:14.0783 Tab (0x09, BIOS 0x0F) UP -> 2ms
20:14.0783 RAlt (0x12, BIOS 0xE038) UP -> 127ms
20:14.0783 Tab (0x09, BIOS 0x0F) UP -> 2ms
20:20.0818 Num Lock (0x90, BIOS 0x45) DOWN
20:20.0818 Num Lock (0x90, BIOS 0x45) UP -> 8ms
20:20.0818 . (0x6E, BIOS 0x53) DOWN
20:20.0911 . (0x6E, BIOS 0x53) UP -> 95ms
20:20.0927 Num Lock (0x90, BIOS 0x45) DOWN
20:20.0927 Num Lock (0x90, BIOS 0x45) UP -> 8ms
20:22.0210 Enter (0x0D, BIOS 0xE01C) DOWN
20:22.0299 Enter (0x0D, BIOS 0xE01C) UP -> 104ms
20:22.0858 Num + (0x6B, BIOS 0x4E) DOWN
20:22.0921 Num + (0x6B, BIOS 0x4E) UP -> 72ms
20:25.0850 Num - (0x6D, BIOS 0x4A) DOWN
20:25.0927 Num - (0x6D, BIOS 0x4A) UP -> 80ms
20:26.0306 Num * (0x6A, BIOS 0x37) DOWN
20:26.0384 Num * (0x6A, BIOS 0x37) UP -> 88ms
20:26.0706 Num / (0x6F, BIOS 0xE035) DOWN
20:26.0782 Num / (0x6F, BIOS 0xE035) UP -> 80ms
And this is how the UI displays the keystrokes from the 23U...