When exporting a project or task to a WSXZ package, the option Allow split and merge is automatically enabled and greyed out. It cannot be unchecked.

Is it possible to control whether this option is automatically enabled or if it is disabled?

The Split and Merge capability should be allowed for translators who can be trusted to change the presented segmentation into more logical groupings when necessary. To preserve the highest level of translation memory leverage, however, you may want to prevent translators from splitting and merging segments.

The Allow split and merge check box does not appear on export dialog if the Can split and merge segments box is not checked in the User Type privileges screen. Therefore, if you do not want a user to be able to split and merge segments, remove this permission from her/his User Type.