So what's your REAL objection? What's the worst that can happen if you test and pass or test and fail?
Obviously your instructor wouldn't be suggesting/pushing you unless they felt you were talented enough. Sometimes we are our own biggest critic. Hence your perfectionism...you have to whole life to try and reach perfection...my suggestion is that you don't let this one speed bump prevent you from that pursuit.
I get the feeling just being rougher isn't the real issue..or you will never test and should probably find another dojo. Fear I think is your real test and that is going to find you at whatever you choose to do. Be the perfectionist and pass the test the first time!