So if I understanding thsi correctly, if I make a reservation using points I still get credits for the nights stayed but if I use rewards + cash for an upgrade I don't get points for the extra dollars spent on the upgrade? I'm pretty sure this is the way it is but I wanted to verify that's it's just as good to use all points if I have them to spend.
That's right, no points for money spent on redemption upgrades nor points for money spent on cash and point redemptions. I think it was pretty lax until the new points and cash redemption option came in but now it's simple:
NO points on room rate when redeeming (other than using instant redemptions)