The issue with firing +P in pre-WW2 HE's is not cylinder strength, which were heat treated after about 1920 but soft steel in the frame and yoke barrel which are only about Rockwell B scale 80-90. Post 1957 guns are generally RC 20-25.
Most of the prewar guns will not be damaged firing only few rounds of +P, a box or two spread over the life of the gun. Not more. Carry +P, but use only standard pressure ammo for training and practice.
High volume use use of +P WILL result in frame stretch and development of cylinder end play. More than 0.002" end play (as measured with and without rear gage in place) accelerates wear by the cylinder pounding against the frame.
End shake is corrected by stretching the yoke barrel and refitting.This increases B-C gap and can usually be done only twice before B-C gap increases to max 0.010. Once end shake increases to over 0.005 it will often produce misfires.
If it were me I would trade the +P ammo for wadcutter and use that because it is the most effective standard pressure load.