I got some Rockler track from Carbatec, and M6 bolt heads don't really want to go in there. Fortunately I got more than enough T-bolts to go with it in the kit. I have what I think are 1/4" bolts also from taking this and that apart, and the heads are too fat to want to fit the track - vertically.
Might be due to US and Brit 1/4" head sizes being different, not sure. Kreg track may well be different for all I know.
In general terms, on the subject of Carbatec NZ, I can only say that the service is very helpful and friendly. The three machines I bought from them (Jet dust extractor, Carbatec 15" thicknesser and 8" long bed jointer) are all solid machines. Unfortunately, the quality control of the boxed machines in MY experience is horrid. Loose bolts, machines not fixed down properly in the crates, motor not fixed properly inside cabinet - trashing it internally. We can't really even blame Carbatec for that, because they obviously receive the machines in boxes that are nailed shut in China. But I feel it really would not hurt if they gave their suppliers a rev-up. This kind of nonsense is not going to do their reputation any good, and into the bargain it may cost them money. If it were not for the 4 1/2 hour drive to the store, I would have asked for a new jointer cabinet, due to the motor swinging off one bolt inside and a clear forklift indent on the outside. :(