We have run a benchmark against kotlinx-html with different parameters --K2 being one of them-- trying to find out how to speed up our builds. The [reasons are outlined further in the README](https://github.com/cies/SlowKotlinxHtml), and there's a [table of results](https://github.com/cies/SlowKotlinxHtml/blob/master/RESULTS.md). This does not suddenly make kotlinx-html reaaaally fast to compile, but it does show how to improve things considerably.