Even if there are no customizations to the contents of the ISPF libraries (try to minimize or avoid ISPF customizations) there will be at least occasional updates to the user authorization load library that should be deployed by ENDEVOR. However, using ENDEVOR SCM to update ENDEVOR introduces a risk that an update to ENDEVOR will bring ENDEVOR down. For quicker recovery when there is an operational failure, a duplicate copy of the ENDEVOR customizations can be deployed as described below. This in addition to a separate testing only installation of ENDEVOR that may reside on a different LPAR.
Create two different sets of ENDEVOR run time customization libraries, install time (bootstrap) customization libraries that are outside of SCM control and corresponding ENDEVOR populated customization libraries. Use ENDEVOR site symbolic values to identify the high level, mid level, and/or low level qualifiers of the names of the customization libraries currently being utilized. Code those site symbolics when referencing the libraries in the processors (for example, //SYSEXEC DD DSN=&#HLQESCM..CSIQCLS0&#LLQESCM).
There will now be two copies of your customizations, one under SCM and one outside of SCM. However, two of the customized program elements will not be identical. There should be two different SCMM@SYM or SCMM@LIB STEPLIB in the two CSIQSENU libraries to reference the different CSIQAUTU libraries and two partially different sets of site symbolics for the processors in the two CSIQAUTU libraries. To also support different PARM libraries (which should be populated by ENDEVOR) there will also need to be two partially different sets of the defaults table in the two CSIQAUTU libraries. Code a variable in the ISPF ENDEVOR startup script to switch between the two sets of startup libraries (for example bootstrap = 0). Normal operation concatenates the ENDEVOR populated customization libraries. Change the value of the variable in the startup script (for example bootstrap = 1) to concatenate the bootstrap customization libraries when needed (usually for a new install or for correcting a failure).