This thread seems to be morfing into PL'ing rather than BB'ing, but Oh well.
Just my view...that's all: If you want to get stronger on any lift, than practice that actual lift more. Not less, like every two weeks. The max, in some special designed programs, being 9 days between workouts. But may be for a shorter training cycle. Keeping the edge (when lifting off the floor) on form and timing, speed/quickness, with regards to the firing off of muscle fiber nerve impulses ,should be kept primed on at least a weekly bases. In harmony with the CNS, insures a progressive strength increase. Strength is not that difficult to gain if you think about it.
If you were to only do the DL (for example) once every 2 weeks, than do GM'ings, SLDL or Romanian DL's, rather than hyper X's only, the alternate week. Want to keep the body adjusted to handling weight in the standing position and as close to the actual DL it's self. These 3 movements bring those fore mentioned posterior chain into play strongly.
If only doing the DL once a week than do them on Monday. On Thursday try GM'ing, SLDL's orRD's. Add a few sets of hyper X's along with any of the three. Hyper X's are a very good movement when included in a all around back program. Good Luck.