PCF8574 keypad with interrupt

[bluevd]

Hello folks,

I'm working on a project involving the usual I/O (LCD, Keypad, 4 tactile buttons and 2 IR detector switches) and a Pic18.
Since my LCD already has a piggyback PCF8574, I figured I'd use one for the keypad and the 4 tactile switches (keypad is 3x4 so I can add another column for the 4 extra buttons).
While googling out the PCF8574 keypad solution, I noticed all examples use constant pooling (even the ones that implement the PCF8574 without a breakout module and thus the INT pin could be used).
Since the key input in my case accounts for less than 5% of the time (just for configuration and function select) I thought I could keep all columns high and tie the Interrupt pin from the PCF8574 to the PIC18. Then, when the user presses any key, it would trigger an interrupt and then I can do the usual pooling of the keypad (thus allowing the MCU to dedicate more time to other routines).
Is there any flaw in my logic?
PS: I'm awaiting for parts so I cannot test the setup yet, though I'd like to get started on the code