Rigorous standardized test?

We live in Pennsylvania and are in a test year (3rd grade). I bought the untimed CAT test because I just needed something to check the box- we're having our evaluation early because I'm having a baby soon. That said, we are academic homeschoolers and I would like to have something a little more rigorous to see if my kid is actually meeting standards. It's my understanding that the CAT is a little...easy? Not sure if that's the right word but a little behind. I wish I could have him take PSSAs with our district but logistics would be tough at this point. Is there something else out there? Hoping for something free or low cost because this isn't a need, just a curiosity thing!