From the looks of it (not ever seeing it in person) it looks like you would just have to cut the "knob" off the bolt handle and thread it, if you didn't want to do this yourself any machine shop would be able to do it.
The issue I had with the Badger was that, with the tapered shape, I actually wound up putting the web of my hand/back of thumb where the knob met the shaft, which basically made the whole assembly shorter in effect.
I liked how the EGW had a beveled ring and "caught" my hand better and farther up, extending the shaft and resulting in more leverage. There's no issue with the Badger if you like to grab the knob like picking fruit, but I was taught to use the back of my thumb-- the additional engagement surface provided by that extra beveled ring the EGW provides is something I personally find useful (and a feature not included in the Badger knob).
It's personal, just like the trigger. Don't feel like you have to go with a Badger if do get an aftermarket bolt knob.