What are the implications of using CONTROL=C and USERDATA=REUSE settings for load libraries under the control of Endevor? Since Endevor footprints should be in the IDR data areas, might not one or both of these settings cause issues?
There are no implications, no issues.
CONTROL=C tells PDSMAN to update member control information (ie, last update date) as members are being updated, including COPY operations. USERDATA=REUSE tells PDSMAN to record control information even when there is non-standard data present in the directory entry.
Endevor footprints are placed in the IDR records of load modules. Since load modules will not have the footprints in the directory entry, there is no issue.
Endevor footprints are placed in the directory entry of non-load members. PDSMAN and Endevor work together so that PDSMAN member control information and Endevor's footprint can co-exist within a non-load member's directory entry.
This is stated in the PDSMAN Installation Guide, in Appendix E, under CA SCM for Mainframe Directory Entry Format.