Multi plane pr/pull and legs question

I'm currently planning out my first SSC. I have my first 3 days of the week as M, Tu, TH and as vertical press/pull+legs+core, horizontal press/pull+legs+core, and vertical press/pull+legs+core (Different exercises) again respectively. I want my final day to be Friday and as multi plane pressing and pulling. However, I am not strong enough to do some MMP/Pr exercises like chest roll. I was wondering if anyone could suggest some basic multi plane exercises to build up off of. I have also read somewhere that I should not do multi plane work until I am stronger. Would you suggest that I change this day into horizontal pull/press?

Also my leg exercises are currently deck squat with jump, box jump, senders, and assisted pistols. Do you think this is good? Are these exercises still supposed to be 3-5 reps? I feel like this will not work out my legs sufficiently on exercises such as deck squat w/jump. Should I be doing this with weight?

Any advice will be appreciated.

If you can't do MPPU you want to work the individual portions. Chest roll is a handstand push up and a PPP, for example.

You can do higher volume for legs if you want, that's up to you. Using added weight is a good idea once you get to where things are easy without added weight.

Do you have any other leg exercise that you think I should incorporate?

You should be dong half GHR at the very least, you have almost no posterior chain work besides what goes on in pistols. You may also want to look into single leg deadlifts and perhaps two leg deadlifts as well. Single leg trains joint stability and double leg lets you load the big muscles more.