PS4: Can you buy PS Plus on the non-primary PS4 and then play the PSPlus games from the primary account?

So: Suppose I get on my Ps4 PsPlus, on which my account is not stupidly primary (share with someone who lives with me) can I then play the PSPlus games from my colleague with my account (primary account)?

The thing is, we both have our accounts as primary, but have not had PsPlus for a long time, but we want to gamble online again so that we can gamble online with a subscription if possible. Does it make more sense for my colleague to get PsPlus? Then he could play online with his Acc because yes subscription and I could also play online and play psplus games from both of us because his account is primary with me. Do I see that correctly or do I forget something?

Is it true that the only disadvantage for me is that I can't upload saved games? And I can't get PSPlus discounts either, but we would buy them on his Acc anyway. Is that all correct?

In short: on which Acc PsPlus get so that he can play online primarily with his account on his account, and that I can also play online with my ps4 on which his account is primarily and can play the psplus games from both of us?

The PsPlus games are also extremely important: can we both gamble when we do his Acc PsPlus? Beautiful or?

Yes I share too and can do that

Okay so just buy thanks from his Acc (primarily from me) and we both can play the psplus games from both of us? For sure?

Should actually go works for me too

You just have to link everything correctly