I basically use the lid for temp control.
Follows sort of the same personal thing I do when using the WSM as a carolina smoker/grill for roadside chicken and the like.
I use the lid to control flares and high heat as needed. Lid on will put out any open flames. I typically don't have that problem with rottis cooks though, lid and vents are used more for lowering temps as needed.
With the rotisserie I typically keep the lid off unless it's cooking too fast, then I close down the vents, put on the lid and slow things up. Watch the meat temps then lid off again to finish.