PPL rest is a great split. The only thing different I have done in the past is I will change my exercises so it would look like this.
P1/P1/L1/R/P2/P2/L2/R Repeat
Iāve also done it as a five day split where i would do 1 legs per week but do different WOās weeks 1/2
P1/P1/L1/P2/P2
R/R
P1/P1/L2/P2/P2
R/R
Then back to the legs1 week.
I would go super heavy legs one week with compounds and legs2 would be extensions/lying curls and less taxing exercises. I found that by doing this when the legs1 day came around I could push really hard.
As the guys above alluded to, you may need to find a way to give your shoulders a bit more recovery before back squatting. Alternatively, you could always consider substituting the back squat for something like a safety bar squat if possible.
I would also perform triceps pushdowns before skullcrushers. Skullcrushers tend to beat up peopleās elbows, so I strongly recommend only performing them once thoroughly warmed up / fatigued from a less provocative exercise
This may be out of the box, but I think my preference would be to split these sessions up and having Push A, Pull A, Legs A, Rest, Push B, Pull B, Legs B. So move one of your exercises for each body part to session B. Iām not huge on doing the same movement twice in the same week.
This way you have much more focused volume, you can push every set to failure and it honestly makes this a much more sustainable and effective split in my eyes.