Hello,
Thanks for your inquiry. We consider iterative calculation of models as a feature mainly used in material flow analysis and modeling of production/process systems, hence a feature typically used in the "Efficiency" version of Umberto. From our experience, it is not much used in LCA models.
We therefore will be providing iterative modeling ("dynamic modeling") or an alternative modeling only in the successor version to Umberto 5.6 Efficiency (scheduled for later this year). The Umberto NXT LCA version does not support this.