Be careful with that. Dispensationalism is just another brand/form of denominationalism.
I believe you are quite mistaken (if not confused) about these terms. Dispensationalism cuts across denominational lines, but it is generally accepted in evangelical and fundamentalist churches as opposed to mainline Protestant denominations.
It would appear that you have not really looked into Dispensationalism in depth, since there is absolutely nothing objectionable about it. It is simply a METHOD of understanding Bible truth. And there are variations in the number of dispensations even among Dispensationalists. The simplest way to under this method of interpretation is to line up the major covenants in the Bible with the dispensations.
At the same time, it is very clear that those who are committed to Covenant Theology, Amillenialism, Post-Millennialism, Post-Tribulationism , etc. are BITTERLY OPPOSED to Dispensationalism. Some even go so far as calling it "heresy". But that is total nonsense. Most of these people have not even studied the elements of Dispensationalism.
What really bothers them is that Replacement Theology (replacement of Israel with the Church) has been exposed as a lie. Until 1948 no one expected to see a nation of Israel back on earth. But had Christians simply studied the OT and NT prophecies pertaining to redeemed and restored Israel, they would have understood that God was not finished with Israel although they were dispersed and temporarily blinded.
Am I a Dispensationalist? Absolutely. There is no question that God has dealt with human beings in different ways at different times. At the very least we know that there is a major difference between the Old Covenant and the New Covenant. However there was no so-called "Dispensation of Innocence" (Adam and Eve) since their stay in Eden was extremely brief (or so it would appear). Neither is there a so-called "Covenant of Works" (Adam & Eve) since God did NOT make a covenant with Adam. God gave him a commandment, and he disobeyed it.