i'm not one for internet arguments and really just want solutions. maybe you could point me at the details for a setup that worked for you?

based on my own testing, dm has a lot of footguns and, with some kernels, as little as 100 bytes of corruption to the underlying disk could render a dm-integrity volume completely unusable (requiring a full rebuild) https://github.com/khimaros/raid-explorations

Well the intention of the integrity things is to preserve integrity that is an explicit choice, in particular for encrypted data. You definitely need a backup strategy.