My honest opinion is you should remove any non-essential baserock, aka any place that is not going to hold coral then it should be only enough to support the top rock. I used the same rock and I knows its very difficult to work with I just broke it up and looked for pieces I liked. All my past tanks I had rock on the bottom and looking back it was just a pile of rock look. Smaller rock is easy to epoxy to the larger base structure and pretty easy to blend in with epoxy.
Ultimately, you need to love it so if you are satisfied leave it alone. If your not happy with it change it before adding corals and fish. btw you system looks great!