I bought a Rike Shadow-T with its modified tanto edge. I sought advice to sharpen it, and especially how to best preserve the transition point where the edges meet. I contacted Edge Pro; Ben replied to my email the same day and offered a free demo sharpening; the knife came back promptly with a wicked edge. Here are his observations--perhaps you'll find them useful (using their Apex 4 sharpening kit):
"Just finished the knife. I am going to classify it as stunning! Much easier to sharpen than I was thinking. Factory bevel was exactly 20 degrees on both bevels. I rested the knife on the slopping FACE of the blade. This lowers the sharpening angle by half of the angle created by the knife. This knife measures 10 degrees. So I set my Pivot to 25 degrees to put 20 on the knife. Most folders do not have enough FLAT for a good rest so I wind up doing most of them on the FACE and just adjusting for the angle change. You lay the knife at the corner of a flat table with the edge of the knife along the edge of the table. Put an angle gauge on the knife and that will tell the angles created by the blade. If the blade has some flat you can start a bevel resting on the FLAT set to your desired angle. Then move to the FACE of the blade and reset your Pivot to your new bevel.
I used the small Knife attachment (SKA). I usually only use it if the blade is under 3" However a lot of knives like your have a thumb stud that get in the way so you just get a better edge with the SKA.
I started with the 400 regular stone and it cut the steel just fine. Then I switched to the 450 Matrix and wet through the 950, 1700 and 4000. It took about a half hour but I really took my time. You can resharpen it in minutes with just the 1700 and 4000. Do not use anything on the edge. No strops or hones or you will need to go back to coarser stones to resharpen."
Later comment: "John, I am very pleased to hear how much you liked the edge on you knife. Even I was impressed by the results. Part of the credit goes to the person that ground the blade. The bevels were so precise and they kept the bevels even and the same on both edges. I have seen a lot of Tantos over the last 33 years and this may be the best one I have ever seen. That is why I was so shocked when it was easy to sharpen.
One thing I did not tell you is I put painters tape on the blade to keep from making any marks on the face of the blade. Most of the knives I get are all scratched up so I just put a clean piece of tape on the EP and this is easier and works really well because I am not moving the knife while I am sharpening

Ben" edgeproinc.com