I don't know what time you have to submit your tests, but I think you don't need days or weeks to prepare anyway. Not much you can do really. All you can do is warm up a little bit and get your concentration back if your mind was elsewhere or dormant for too long
I spent two days doing different tests, but it didn't help me get any faster, which is what I needed. All tests I did online as preparation, came as 80 to 90 % correct, even the hardest ones. But if I get these two 75% correct (out of all questions in the test) I'll be lucky. There were 3 or 4 diagramming testlets I finished comfortably before the time expired, but with others, I struggled and made couple of guesses too. Did a bit better with spatial though.
Not too optimistic, but I might squeeze in, just.
EGLC, did you get your results?