I have pulled out the lighted panels in the cabins behind the seats, that made some room for cabin stuff (or fishing poles in the cabin if you're into that), but for a complete bimini top with brackets I don't think it would help a lot.
I saw one bimini boot storage deal that looked pretty good, and slid all the way back to the rear of the hatches, but I don't remember where. I'll dig a little to see if I have something on it.