Post Big Blind Annoyance

I've just joined a Holdem table at Doyle's Room and I want to play. To do so, I will first have to post blinds. Soon the system will check to see if I have done this yet or not, and if I have it will let me play. While it checks and waits for me to decide, everyone else at the table waits as well. The final cut off point is still a minute or two away.

The annoyance is, I already know what I will do but I can't do it until the appointed time, and then I only get 10 or 20 seconds or so to press the button. I want to be able to declare my choice when I join the table, not some time later.