i want to make my google sign-in is floating, but cant find the right title. (title got delayed)

[benizukebeni]

i want to make my google sign-in is floating, so i set this in mango.conf.

windowrule=isfloating:1,appid:firefox,title:Sign in.*

but it doesn't work.
because it titled as "Mozilla Firefox" before changed to "Sign in - Google Account....."
of course, it will affect all firefox window when i change the rule into:

windowrule=isfloating:1,appid:firefox,title:Mozilla.*

what can i do so i can make my google sign-in is floating.
is there any example for something like this?