Matt, have you reduced gassy foods from your diet? Have you tried Beano when you eat cruciferous vegetables? Have you tried reducing or eliminating the fiber, at least as an experiment? Have you tried substituting a very different kind of fiber (e.g. Benefiber)? Have you tried a probiotic? Have you discussed the possibility of SIBO with your GI doctor?
Don’t do all of these at once. Try one thing at a time, and be patient.