Yes, but you can see the area at the top of the IO is cramped in as a result....but it is pretty good as only some audio ports look to be blocked and they are not used anyway.
The method would work really well with a board that has low profile IO. Could nicely finish it off using similar method to how I do my mATX kits. Suspend a trim plate off the 2 x 92mm fan carrier with a couple of 10mm standoffs to give a three quarters border to an IO shield. Could trim the raw surround of the case with a bit of edge trim (like on fan blow holes) and it'd tidy it up a bit more too.
In fact, I've changed the motherboard not long ago (had a Gigabyte 880 mATX when I put up the mod) ; on this AsRock z77 model, the PCI-E 3 port was very close to the CPU socket.
So to be able to use the PowerMac G5 genuine PCI slot for the TITAN and the PCI-E 3 port (and not a PCI-E 2 with my Grail GPU), I had to un-glue the G5 original stands-off, relocate them higher ; that's why there is so much space below, when you look to the I/O cut.
The aquamac solution would have been the perfect one, but I'm not skilled enough to work metal like that ; I tought instead, using long and thin plastic sticks to dress-up the I/O nasty cuts.
Indeed, I'm not using the audio plugin since I'm enjoying the sound capability of HDMI connection and Nvidia High Def driver.