I`ve never seen this done , or done it. Wondering why a guy couldn`t stabilize the tube and drill it ''before'' the peening process . ???? The hole would still be there, but in a diff. location on the sleeve
The first bore that you peen does rotate slightly. Their is also sort of a smearing that goes on as well. I do not think you could do a very good job trying to add the holes before peening the tube.
After one bore is peened the tube will not move.