Juan de Fuca follows a convection rolls division line.
This arrangement is comparable to the Reykjanes Ridge and the volcanic zones in Iceland.
The ridge does originally not follow the main division line, because it is down-welling and therefor convergent.
The position of the two ridges can be compared:
Note that the main ridges are mainly found 1.5° west of the division line between large convection rolls of lower mantle.
Same kind of shift from western side to eastern side, a jump of 3°, is found in both cases. From the Reykjanes Ridge, a jump occurs to the East Volcanic Zone of Iceland, but at Juan de Fuca, a jump of 3° is found for the Gorda Ridge.
The fact that Juan de Fuca and Reykjanes Ridge show two aspects of consistency, that is they both follow the same formula of alignment, and are found 1.5° west of main division lined of lower mantle, is an argument for siting that the model is in harmony with real circumstances within the Earth’s mantle.
For referenc, look for instance at