Ok, I've studied it just a little bit... and you made a little "typo"

     1H   -  2NT

   4C/D/H = void ( where 4H = Sp void)

 

But I suggest a little change..... ( as I am prone to do)...

 

  I would make those "stiff showing" bids mean "stiff OR void" ...

  and   4C/D/H  = 2nd 5 card suit  and 4H would mean 6h/5s .