I would suggest that everyone atleast solve the free test from LSAT site and the daily LSAT question on
https://www.lsac.org
LSAT questions require reasoning and we cannot get it right without reasoning. You have to say that this is so and that is so and so this is the answer. In GMAT since we are used to questions of the same type we generally know the answers. Any bouncers on the test day can be painful. But if you can solve the LSAT questions then you will see the improvement in your GMAT reasoning. Also do not time solve the LSAT. Just take your time even if it demands 1 hour for the question to be read and reasoned.
My CR has improved a lot just by solving 26 CR free LSAT questions. The same is true for RC. After all Law is unlike mba where its only the LSAT that matters.