Cognitive-motor interference research investigates the interaction between cognitive and motor processes. A novel approach analyzes balance control parameters while participants stand on a force plate using an event-related method to examine the influence of single cognitive processes on balance control. In the present study, we applied this approach to a cognitive dual-task paradigm combining a visual-vocal short-term memory task with a delayed vocal response, with an auditory-manual reaction time (RT) task. We varied the stimulus-onset asynchrony (SOA: 100 vs. 1,000 ms) between the targets and task load (report vs. ignore the visual object). Additionally, task load varied unpredictably (trial-by-trial) or predictably (in blocks). This hybrid psychological refractory period (PRP) paradigm created a processing bottleneck during memory consolidation of the visual object and response selection of the auditory target. Auditory-manual RTs increased at short compared to long SOA and during report compared to ignore trials. Force-plate data showed that participants were less likely to adjust balance during cognitive task processing and more likely after task completion, independent of a cognitive bottleneck. However, we also showed that the differing (previous) trial length of report vs. ignore trials lead to a different course of force-plate data. In a replication experiment, which keeps the length of report and ignore trials comparable, we expect to replicate findings from our first experiment and eventually find an influence of the cognitive bottleneck on balance adjustments. With the replication experiment, we want to further investigate whether balance control flexibly advances or delays balance adjustments based on cognitive demands.