Since it became obvious that BO and some of xir's fellow mods are not budging on their convictions I'd like to suggest a more productive and calm approach: transitioning – meaning a process that is not sudden, irreversible, or against sentiments.
Here are my three proposals to the users.
1) If you are about to make a thread on leftypol that you are proud of, or think that is important or offers unique opportunities for lengthy discussions, then submit it to bunkerchan.xyz first (just copy & paste your text) and provide its link in your leftypol OP.
This would encourage users who are interested in your topic to check out both sites and follow the discussion in parallel. The differing post speeds of the two sites might also result in differing qualities.
2) If you see a thread-relevant post or thread on bunkerchan.xyz cross post it.
e.g.:>your mom is GayGay!
Well, actually, as https://www.bunkerchan.xyz/leftypol/res/140.html#q146
points out, you are wrong.
3) Adapt your mee-mees. Include both bunkerchan and leftypol in your images and videos.