There is https://community.bistudio.com/wiki/setSimpleTaskAlwaysVisible, but it only affect 3d
See also https://community.bistudio.com/wiki/BIS_fnc_taskCreate
visibleIn3D: Boolean - (Optional, default false) true to make task always visible in 3D
However at times you dont want the tasks to be visible in 2d (ie overlap with strategic map locations) but only in 3d space
Atm to have it not shown you can achieve only by providing no position to the tasks, but thus its also not visible in 3d space