As stated in the Linked Thread it was attempted every whichway:
The Projection failed to appear on the four Faces
The ‘rounded’ Face was the only one to accept the Projection as expected.
The others aligned a copy of the Sketch with the angle of the Face but offset from the Face.
Several attempts to treat each of the four Faces individually, in pairs and all together ultimately caused S3D to Crash.
The File has been Uploaded for investigation.
There was no ‘square on’ Face available for the above ScreenShot a suitable face was created.
Note that it also projected to the Rear Face of the Main Body.
Having selected all three Faces it was anticipated that the appropriate portion of the Projection would appear on each of those Faces:
S3D was exited and restarted and also the iPad was Closed Down and restarted, after each scenario the processes described in the Linked Thread were carried out.
In the Linked Thread the Projection portion across the Rounded Face was the only one to be successful.
In the above test the Projection with all three Faces selected failed as shown:
If a single Face is selected the Projection appears as a single full replica of the Spline on the same Plane as the Face but offset as shown.