Balsa provides a rapid development flow, where asynchronous circuits are created from high-level specifications, but the syntax-driven translation used by the Balsa compiler often results in performance overhead. To reduce this performance penalty, various control resynthesis and peephole optimization techniques are used; in this paper, STG-based resynthesis is considered. For this, we have translated the control parts of almost all components used by the Balsa compiler into STGs; in particular we separated the control path and the data path in the data components. A Balsa specification corresponds to the parallel composition of such STGs, but this composition must be reduced. We have developed new reduction operations and, using real-life examples, studied various strategies how to apply them. This research was supported by DFG-project 'Optacon' VO 615/10-1 and WO 814/3-1.This report is the full version of the extended abstract [1].