Must replace the U-joint because of the spline shaft difference on the rack side.
Fortunately, the column side is the same so no need replacing.

Strictly speaking, the rack boot spec is different between EPS and manual rack version but can be left as is.

If the EPS rack is still in good condition, can just disable the controller.
Should not trigger the EPS light.
However, please keep eye on the condition of the rack boot.
One of the cause for the EPS rack failure is the moisture entering inside due to torn boot.

Interesting to see different view depending on the driving environment.
In Japan, many owners went the other way.
They wanted the EPS so much that they swapped their manual rack with EPS even on few Type-R or trackday cars.

Kaz