Hey Mei,
Regretfully, there is no option yet to change the x-active delay. The option we have is only the dropdown animation but I believe that doesn’t answer your concern.

The delay I believe is in place so that if the user accidentally moves the mouse outside of the dropdown, there’s still time he can go back. That behavior is a common problem in user experience and that is the solution.
I’ll add your concern as a feature request so if there’s enough demand for this option, this might be considered in future developments.
Thank you for understanding.