Hello FelixPQ,

I'm not sure whether I messed up somewhere else in the procedure but when coming up with it I found if I rotated the cylinder to keep the cutting edge that is parallel to the seam of the cylinder a bit away from each other I could get the desired result consistently. I don't know if I'm just imagining things but it seemed I had more trouble when I had the cuts getting very close to seams in the objects to be cut.

The shrink trimmed surface command seemed to help in the Boolean operations as well, however it is more habit for me than anything else since when exporting AI it makes the intersecting lines of the drawing match up correctly.

I wouldn't depend on my explanation or validity of these explanations, since I have no basis to say whether the extra procedures have a bearing on the successful outcome of the project or not, they might work quite well without them, but it probably doesn't hurt the process.