When the incremental flow is enabled, only new incremental-friendly suggestions can be applied in the subsequent steps. This limits the amount of change that a suggestion can achieve, so large timing improvements are unlikely to be seen.
If suggestions are applied at opt_design
and the incremental flow is initiated after, larger impact suggestions can be applied.
It might be necessary to disable the suggestion because it might cause timing
degradation.
If the automatic incremental flow decides to use the default flow because of a poor quality reference checkpoint, all suggestions can be applied.
Note: The QoR Suggestion and Incremental flow is
supported for UltraScale and UltraScale+ only.