Yes I agree the ISPF stats would be help full. To have both would not be possible technically.
As I said the ISPF stats and footprints are applied to the directory space. As per my memory. Each member(non load) has a directory entry. It has the TTR (this is the physical start of the member) I think another for the length or end. Then a entry for the length of the directory entry for this member. The ISPF stats entry has a specific length. Endevor's footprint has a different length. ISPF edit/browse etc will read member names and look for the specific length of the ISPF stats. If it doesn't see that length it will assume that no stats exist or they are invalid stats.
So we can't add to the end of the ISPF stats directory that will change the length. We want to use the directory space as this will change when ever a update is done to the member.
May I suggest a alternative to ISPF stats. Open a communities IDEA for a method to show the Endevor footprints while the user is in member list with ISPF Browse/Edit.