[EdZ]

Just saw your thread/question - literally seconds after replying to the extensor action thread on this very issue

Not to double post, but yes the 'swinging club' provides the work - for swingers - to maintain exensor action. Personally, I think the 'swing' must be there as well for hitters. To the extent that you can do so, lack of any tension beyond that needed for structure is wasted effort.

Lack of tension can make up for some mistakes earlier in the swing, letting the physics of the 'swinging force' take over. Much easier to keep your timing/tempo if you are free of tension and 'flowing' with the club.