@jbkitzy1 First, I would recommend using Sure Gel, it is a better binder for cured meat than Carrot Fiber which is really better used in fresh sausage. It can be used in cured sausage but sure gel is the better option. Second, 70% venison and 30% pork is going to leave you too lean, you need more fat than that. Go 50/50 with venison and nice fatty untrimmed pork butts, even that will be on the low end of what you want but it will work. You were most likely somewhere in the 10-15% fat range when you want to be in the 20-30% range. The fact that they dried up on you and the meat was crumbly are indicators that it was too lean. Also, remember to mix until you have really good protein extraction, the crumbly texture could have something to do with that, or if you added ECA and mixed too long that could have done it as well. The encapsulated Ctiric acid needs to be added during the last 60 seconds of mixing, this is because we don’t want to rputure the coating on the citric acid or the acid will interact with the meat too soon in the process.
If you do want to try making a lower fat summer sausage you can take some of the principles from this video and apply them, notably using cold phosphate to increase the water holding capacity of the meat. Just know that adding that will cancel out any citric acid you are adding or any other pH dropping ingredients.
https://meatgistics.waltonsinc.com/topic/235/how-to-make-juicer-meat-products?_=1603748529130