1) Back up all your Reaktor VST dlls.
2) Look at them in explorer. You will notice that the FX, Surround and 2X8 versions are much smaller. I take it these are shells that load up the main dll which is much bigger.
3) Load the FX 2in 2out and Surround 6in 6out versions in a hex editor such as Breakpoint Software's Hex editor. Do a byte wise file comparison, stepping through until you find a difference where the FX reads 2 and the Surround reads 6. If I remember correctly I found this at 1183h.
4) Modify the value in the Surround dll to 16, that is, hex 10. Save the file, renaming it to indicate 16x16. When I loaded this hack in Plogue Bidule and in AudioMulch, 16 ins and outs appeared and I could use the pins successfully.