Is there a gadget that will let me slide my seat forward more than my post allows? So I'm I'm trying to dial in the fit on my road bike to be more tri-bike like, and in doing so, I'd like to move my seat forward, well, more than I currently can.

I have the Redshift seatpost, and I really like the dual position action, but it just doesn't go far enough forward for me to hit my ideal position. Truth be told, my bike doesn't fit me as well as it should, but it's currently a better option for me to try to make it work than find a new bike.

Anyway, in my searches I came across the M2Racer Power Module which was apparently a product about a decade ago. It looks like exactly the part I'd like to have, but I can't find anybody selling one. Alternatively, is there anything else out there that would give me a similar effect?

For what it's worth, I've investigated flipping around a setback seatpost, but the Redshift goes forward further, and I've seen the Profile Design FastForward, but I don't think it will give me much more than my current setup.
No. Based on your question and your comments, there is not a product that does what you are seeking (get your hips over the bottom bracket). The reason being that no one rides that far forward.1 The old style Profile is probably your best bet for getting forward:



There are designs with a seat over the bottom bracket, even some that are made super-adjustable in that regard:



Even at that far forward, the hips are behind the bottom bracket:



With that in mind, a reason that most people don't ride that far forward is because moving yourself that far forward screws with the bicycle handling and puts you too far over the front wheel. Note that bikes that enable the most aero positions, like those pictured above, achieve the effect not by moving the saddle forward, but by moving the bottom bracket back.

Now, with all that lecturing done, I would say that if you are dedicated to this experiment, you can get close with the profile seatpost mentioned and an ISM saddle. The ISM is an anatomical design with two points and a gap between. A lot of riders slide forward on that saddle and hook their sitbones on the two points. This is opposed to traditional time trial saddles which just had more padding on the nose meaning that sliding forward just jams that thing into you perineum. Even better is if you can start with a bike with a steeper seat tube.

1That is a bit of hyperbole, perhaps someone rides that far forward.