If you're not ready, don't assume the start position. I simply keep my hand on my gun until I'm ready. I find short buzzing to be much more of a problem when I have to respond to are you ready. I get standby-beep while I'm resetting from responding. I've gotten better at it because some SOs seem to be stuck on requiring a response. This is all personal preference stuff, but I think the USPSA rules are the way they are because it tends to be the preference of those who care enough to be involved with rulemaking.