In any tournament not in my home centre, I always put a 2nd singles entry in. I mean, so what if the shot is better the second time around. The squad times & oiling times are usually on the entry form, otherwise it only takes a question of the tourney director to find out when they're being oiled. Do a little bit of research into the kinds of patterns the centre usually puts down & plan your squad times around that.
A little bit of study before a tourney can go a long, long way.
GL & HS
Big B