My advice, DO IT! Seriously, first chance you can. I know for a fact that of the three drafting companies in my team, the very first question asked when we are reviewing resumes, does he/she have any Solidworks certs? If they do, they go automatically into the review immediately pile. If they don’t, they go in the review at a later date pile. We interview the ones with certs first, unless there’s someone with a ton of experience but no Cert, then that person typically gets first interviewed