I'd say let Boomerang go. It sounds like you've done all you can do to make that situation work.

Illumination and Writers' Blokke are two that have few filters as to what they will and won't publish. So you may want to try them if you haven't already.

Yes, thie like many online sites is very much left so I keep my thoughts to myself on that front. I wasn't for the right until the left got so fanatical about things. That turned me off and pushed me to the "other side" which is has done to a lot of people. Too bad the left doesn't see it that way.

You could always start your own publication. Your pub, your rules. So you can write about whatever you want to as long as it doesn't violate Medium policy.