Now you can !
You can now go up to 20 Gb for a Unicode PST, 1.5 Gb for the old-school “2Gb max” ANSI PST. And yes, it works
Here is a nice picture of two exports of the same archive .. One where I picked 2.2 Gb for the size, and one where I picked 3.6 Gb for the size of each PST :
Photo from: Stuart Miles