The duct should comprise a plastic tube that gets surrounded by concrete then screed and flooring finishes are applied above. The air and suction lines remain accessible via access covers.
Of the 6 fixings to hold the chair down, you'll probably find that only 3 actually do any work as when you tighten one, the adjacent ones slacken off. By repeated torquing, you'll get them close to equal tightness but it'll still just be close. That's why installers use break-back torque wrenches (if they're following the instructions) rather than dial-indicators which should only be used by people who actually understand what they're looking at.
I loaned an installer a dial-indicator once. Several hours later, he'd managed to pull all the fixings out without having exceeded the recommended torque.
Back to the issue of fixings coinciding with the channel, just make sure that they're deeper than the channel. And miss the duct, obviously.
I know what it should be, however it does not appear to be the case that it will be that option.
The 6 bolts are split 3 and 3 down each side of the service component and of the chair.
It is one entire side of each that will be overlying the duct. Not so bothered about the chair as it has a fairly wide base but the service component has a narrower base, and will have the light and bracket table on it, so far more lateral forces at a greater height.
Next solution is bolting a large metal plate to the floor which has bolts welded to it in the right places and then nuts to secure the chair and service component to the plate.