And that was the same reason why I used it even though the recipe didn't call for it :) Good to know that my instinct to be safe rather than sorry was correct...I was just wondering if there was an actual risk given the type of curing and now I know to keep using it.
In any case my recipe was as follows for 5.51 lb or 2500 g of top round.
2.5 kg top round or london broil
6.15 gram cure - 150 ppm by weight
145 gram Kosher salt - 6% salt by weight (cutting this down to 5% next time)
75 gram light brown sugar - 3% sugar by weight (this will go to 2.5% next time to keep the ratio correct)
141.75 gram Malt Vinegar (1/2 c for 2 kg)
70.87 gram Worcestershire sauce (1/4c for 2 kg)
5 mL baking soda (1 tps for 2 kg)
3 mL ground white pepper (1/2 tsp for 2 kg)
15 mL ground roasted coriander (1 tbs for 2 kg)
I mixed the malt vinegar, Worcester sauce and cure together and dipped my meat slices in them, then laid them down in a bed of the mix of salt, sugar and spices. I kept laying down meat and salt mixture in layers until done and then let this sit in the refrigerator for 12 hours. Then I moved the entire mixture to gallon bags and mixed together the salt and liquid and kept rotating the bag from side to side for the next 12 to make sure all the meat rested in the cure for at least a day. Then I laid it out on paper towels to dry for a few before putting it in the dryer and with the fan going it took only a day to get to a "wet" consistency I liked, at that point I pulled it and vacuum packed it to freeze.
As I said next time I'm going to go with 1" slices and let it simply dry for longer to get a thicker end piece.