Exteriorization is an EP for the process Opening Procedure by Duplication, but is not the only EP. The reason Op Pro by Dup had an EP of exterior was because we didn't have Int-Ext then, and had to end it off on the first exteriorization.
The EPs for OP PRO by DUP include:
A. Flattened Comm lags and no more change on the process (per PAB 48).
B. A real big win with F/N, Cog, VGIs and ability regained (per HCO B 20 Feb 70, "Floating Needles and End Phenomena").
C. Exterior with an F/N, Cog, VGIs.
In the presence of heavy overts, it is possible that a pc won't exteriorize on Op Pro by Dup.
Overts are handled on Exp Grade 2. Op Pro by Dup could grind on and on for as long as 50 hours with no change in an attempt to run it to Ext, when it's an out Grade II.
Nothing in this BTB should be used to quickie Op Pro by Dup.