I did start building Lesti_Fpc2. I always wanted a flexible and most compatible solution for Magento. That was never easy. So in Lesti_Fpc I did use the event controller_action_layout_generate_blocks_before as anchor. Just to explain, as anchor I mean the point were the Full Page Cache stops normal behavior of Magento and sends cached response. Normally you want to have this anchor as early as possible. My anchor was very flexible, but also not that fast as I expected.
I just was thinking about Fuzzy Search and why it isn't possible in mysql. Sure there is SOUNDEX in Mysql, but that's not what I want. I want search results from the Levenshtein distance. But Mysql didn't has such a function. I guess the best solution would be a search server like SOLR or Elasticsearch. But on a shared hosting you haven't such a cool thing. A possible solution is to return all results of the table and work with the levenshtein function of php. I guess in the most cases this is the best solution. But I just want to test an other way, I guess maybe a very stupid way.