Hello Tom,
Although not specifically used as a tenderizer and more for flavor, I have used Worcestershire sauce as one component in my ingredients. This contains vinegar as you know, which is a chemical tenderizer and will help to break down the collagen in meat. I am unsure of the effect based on concentration, but certainly something you can experiment with by adjusting a vinegar content. Be mindful of the effect on the flavor, so balance with other ingredients!
Other tenderizers are enzymatic like McCormick's, which contains Bromelain, Papain, or other fruit extract. These will also help break down the meat. I have not tried anything like this as I like the jerky chewy, so I cannot advise on how much to use. Since I also brine for several days, not sure the effect of time with these enzymes. Another drawback is the effects of these enzymatic tenderizers are stopped by cooking, where higher temperatures inactivate the enzymes. Since jerky production is a drying process, you likely will not reach a sufficient temperature to stop the effect, and they will continue to tenderize until they are depleted.
For a mechanical tenderizer (mallet or blades), I would imagine this would be effective and may give you a product you like. Since this is very simple, give it a shot and let us know what you think. If the results are inadequate, I would then move to chemical, and lastly enzymatic, in that order based on simplicity.
Let us know how you make out!