I found a way to disable partial data collection midway. This is especially useful because credits are consumed even when very little data is generated. So we can enable partial data collection only after a certain amount of blocks have been performed and disable it until those blocks are completed.
I needed this especially because my practice and main experiment are on the same link however the practice data is not needed and furthermore we ask the participant to abort the experiment when they are done practicing (hence the unnecessary consumption of credits)
psychoJS._config.experiment.saveIncompleteResults = false; // disable partial data collection