As posted earlier (in a different thread).. I've gone this route. Union's customer service is top notch and they did offer to send me the older force caps. However, I've had some gift cards laying around for a bit and I really like the burton caps.. so I went that direction.
The Frankenbinder process was much simpler than the link posted. The Burton getta grip cap and ratchets actually work with the Union ladders. No mods were necessary and it was as simple as screwing the Burton caps into the Union laders. I still need to adjust them for my boot but this is the result:
(*flux's I ordered were over sold and really missed SL's after riding my Cartels again)