While I'd love to be able to tell you that you can use any top you wish with this headset, that's not the case. A threadless headset top cap has a much easier job than the top cap in the inni headset. The former merely has to withstand the headset bearing preload forces and only until the steerer clamp bolts on the stem have been tightened. It can be removed at that point if one so chose to.

The inni top cap is more like that on a standard threadless adapter: it has the support the wedge which is anchoring the quill into the steerer tube. This is a pretty critical job if you can imagine and the top cap has to be designed to support that load. The early prototype top caps I made were designed around an M8 socket head cap screw, much like you'd find on a threadless adapter. The new top cap design use an M8 stud integrated into a broached aluminum cap, which I think looks far cleaner and left more room for logos Nearly every threadless top cap is designed around an M6 socket head cap screw. The latter also use much thinner cross sections as they simply will never see the kind of loads that a threadless adapter or the inni top cap will see.

If you want to customize your headset, let's talk and perhaps we can get you what you want without compromising the design/safety.