Yo Piccioni,
The big question is what do you really want from all this training? Noteby, you can’t have everything because we are not superhuman, haha!
Now for my long response:
I understand, the MP programs are a quite different from your usual general public basic programs. I am familiar with SS, 5×5 and such. They are not bad programs. In fact, the principles from these basic programs are built into MP!
Adding your suggested exercises won’t hurt but then it is not considering what the MP programs are made to do. One can say you can’t call it an MPFPT program if u add stuff and we are not liable for whatever result you get, good or bad. If you do insist upon yourself to add, i would do it after you finish the MP session. That way, you at least go through the MP program in full and then go do your own thing.
Our exercise selection works a whole lot more than a simple tricep extension for example. Another way of saying it, we have considered such exercises and deemed them less fit for purpose in terms of return of investment.
I was like you, reluctant to try this new stuff because its so foreign but I told myself i won’t see the claimed results if I don’t follow what is prescribed. So, try your best to trust the program and go through the learning process. You will gain far far greater knowledge than just a training effect by allowing yourself to learn new things, especially when we say these exercises are very suitable for Ultimate.
In the grand scheme of things, you are only 17. You have lots of room to grow and at the best period in life to try new things.