Chayey Sara 25: 02-04 16 more children (nations) from Keturah

Chayey Sara 25: 02-04 16 more children (nations) from Keturah.
Why does Avraham have 6 more sons and ten more grandchildren from Keturah?
Yitzchak has already been ‘purified out’.
Two extremes:
1) these children represent a very severe evil that Avraham could repair better than Yitzchak (so he volunteers to do this).
2) these children are virtually Kedusha and ‘will serve’ when Moshiach comes, and this is why they are brought into the world.
Each name of each child is explained twice based on the3 aforementioned two approaches.