IriusRisk automatically calculates the countermeasure priority based on the associated threat with the highest risk. Since version 4.2, this priority can be overridden manually. To distinguish between the two types, IriusRisk displays the word "Calculated" next to the priority rating for calculated priorities:
Export / Import
The manual value is accounted when exporting and importing projects and templates. (There is an attribute for countermeasures with the value of the manual priority, when the project is exported. If the priority is set to calculate, the attribute is empty. When a project is imported the attribute defines the priority set manually)
Send to Issue Tracker
The selected priority (manual or calculated) is used when an issue is created in the Issue Tracker (the correspondence between priorities will depend on the priority values defined in the Issue Tracker).
You can find more information about the priorities in this linked article