As for Entralink abuse, ToastPlusOne's Eon Timer supports Entralink mode. Just check off the High-Link box on it. And it's basically just like C-Gear abuse except that when you start your game and it asks you to turn on your C-Gear you say "yes" and sit at the menu right before entering Entralink, pressing A at the end of your second timer.
Frame advancements are odd. Instead of the usual target frame - 3, it's either target frame - 10 or target frame - 23. I haven't quite figured out what determines which frame advancements. My math might be a little off, but basically you want to be either 8 or 21 frames before your target, and the C-Gear advances the RNG by 2 when you turn it on (hence the normal starting frame of 3).