That is a thought, and it wouldn't hurt if OP truly voids it at the end. I know a decent handful of people who went in with the intention of voiding and didn't (like you mentioned) and fully regretted it. They didn't void because they suddenly felt wrongfully confident with their exam or they were so exhausted by the end of it they didn't want to relive that experience and so didn't void. Do not fall into these traps OP if you do decide to do this.
Just remember OP voiding doesn't give you any score or results, so its purpose would be for getting familiar with true testing conditions and even possibly your testing center if you do reschedule for that center. It could give you an ease of comfort on the actual since the experience wouldn't be completely new to you.