Well, knitting squishes.
But yes, 90 is a lot for straight needles, and it gets very heavy very quickly. I had over 120 at one point on 24" circs for my last FO, and that was enough!
So, you're one of those people who practices? That's awesome. I don't have the patience. I predict that you're going to be someone who, when you launch into your first project, are going to be reasonably confident and competent, and not have to frog endlessly.
So whatcha gonna make?? I know we're all curious!