I was just thinking about dispensationalism—I’m sure you ‘just’ do the same all the time ;-)—it is in my life blood, as I have shared multiple times before. It is interesting, maybe you haven’t made this connection before, dispensationalism is necessarily a product of a Christian Fundamentalist doctrine of Scripture, and in particular, a staunch and idiosyncratic adherence to verbal plenary inspiration, and thus then, the inerrancy of Scripture. What’s at the bottom of what Charles Ryrie has called the sine qua non of Dispensationalism—i.e. adherence to a wooden literalistic form of interpreting Scripture—is that whatever God has said in the any part of Scripture, must occur with positivistic emperical fulfillment, or God has lied. And so when God promises in Jeremiah 31 that the nation of Israel will always be His covenant nation, then it is impossible to read this sensu plenior through a fuller meaning in light of its literal fulfillment in Jesus Christ, and in the way the New Testament authors interpret New Covenant language in that light. So Israel must be the focal point of prophetic history, and as most classic Dispensationalists maintain, there are multiple prophecies yet to be fulfilled; even though, it would appear that the New Testament believes the substance of those have already been fulfilled quite literally in Christ.
In short: What’s at stake for Dispensationalists is the belief in the integrity and Sovereignty of God. If one jot or tittle of an OT prophecy is not fulfilled wooden-literally in the nation of Israel; then God is a liar, the Bible is errant, and we are of most people most to be pitied. Maybe this will give you better insight into what’s at stake for the Dispensationalist hermeneutic; a doctrine of Scripture, and more importantly, a doctrine of God.