My use case is that I want jenkins to automatically build new tags when they are created, so jenkins should somehow automcatically choose the latest tag.

The "List Subversion tags" already allows to limit the tags to only 1, and with "Sort newest first" it actually shows the latest tag, but this cannot be chosen automatically.

To select the latest tag automatically I can think of an option "Select newest automatically".

This build param (newest tag) should be used in scm polling and also when a manual build is triggered.