Well I kind of like things the way they are atm, managing minutes for good game shape is one of the hardest and most challenging things in this game, and I wouldnt like to see it simplified too much... Of course only my opinion, and I probably am not the right person to discuss this because I play 99% of my games with max 7 players, but still, I believe that it will kill one of the most important, and most amusing game aspects for me:)
The idea of this proposal is to have you full squad at disposal while playing your starters on +20 situations.
It´s not intended to manage efficiently game shape, on the contrary, this option would provoke worst game shapes but you decide ultimately if you need the basket average or don´t want to risk the rare case when you lose a +20 lead game (rarely happens but this would help to reduce its risk).
Also NT would benefit from this option.
PD: Mmm maybe he´s not that bad but it´s still debatable. Not an OKC fan but I would play Adams/Collison before always. Never seen an NBA player jumping like he was 60 years old.