I run those shifters on 2 bikes. The cable tension setup is the same as normal shifters, no additional tension needed.

The only difference is when the cable is totally de-tensioned, like unhooking the derailleur. If not in the small cog/chainring position, the cable hook can swing outwards and jam against the outer body.

Shifting to the neutral position before doing any work will prevent any issues. If it does get jammed so bad that jiggling doesn't work, it's easy to remove the shifter unit from the bracket.