Does the bag look and feel dull and dry? Or are you just concerned that the leather sequins might lift or curl and dry out? I don't have a bag with leather sequins, but I would be cautious about using any creamy or pasty leather products because it might build up and look nasty.
When I have a delicate leather bag to clean or moisturize, I tend to use Lexol products - they are thin and light-weight and work well on many different leathers in my experience. Lexol does have a bit of a smell but it fades quickly.
You could also try posting your questions in the Rehab and Rescue thread to get some additional opinions, good luck!
https://forum.purseblog.com/threads/coach-rehab-and-rescue-club.833400/