I'm trying to get my ducks in a row so I can get off the grid long enough to visit HK in Tijuana at the end of the month. I'm going to be in San Diego on the 30th.
I have a passport book but not a passport card. Will I have an issue getting back through the border with the passport book as opposed to the card? And if not, how hard is it to get a passport card within 10 days?


You'll be fine with the passport book. That's the real deal and what you want to have to visit foreign countries all over the world.
Besides, It would take you longer than 10 days to get the credit card sized passport that allows you to travel to Canada and Mexico... (Unless you work for some secret government organization).