I mean you did the same test twice and gave yourself extra time. Of course you are going to perform better. This doesn't mean you will perform better for a totally new test.
I argue that patterns learned on individual tests would apply to new tests. There are a set of patterns which have already been called out here. Translation, rotations, exclusions, logical and/xor on line segments and dots, etc. IME, most IQ tests sample from this set of patterns. Once you are familiar with that set you aren't really doing a first-order matching - instead you are going through your list of expected patterns and seeing if they apply to the particular question. This means you can breeze through the early questions drawn from that set using your memory and then save your cognitive time for the later harder patterns.