RE: do i need to SLDL if deadlifting and squatting?
Hmmm tricky one, if like you say BYF1 you feel your lowerback doesnt fully recover then maybe you should skip the stiffies. Alternatively I suppose you could swap you deadlift for a rack pull or something, maybe a power shrug?
I'm pretty sure I injured my lower back from simply overtraining it, oly lifts one day, barbell rows the next and then deads the final day. (not on consecutive days by the way)