Currently Flavour is based on TeaVM 0.6.1. This is a solid, stable release that has been used on many projects for years without problems.
However, TeaVM has made new releases. We need to investigate the features, performance, and bug fixes in these newer releases and determine at which point the effort required to adopt these new releases is outweighed by the benefits they provide. Note that these are breaking changes in the TeaVM releases since 0.6.1, this is not a trivial POM-only upgrade.
Upgrade instructions are now here: https://frequal.com/java/EnablingFlavourInJava1117And21.html