Good afternoon, jvelezmorales!
Yes it is possible. I struggled with this for a long time and I succeeded. It is necessary to merge both keytab files on the application servers: one from the haproxy and the other from the application server.
Described in more detail in Client Negotiate -> haproxy -> kestrel (Debian) ->401
If you have any questions, write, I will try to help. Everything works for me as it should. Two IIS (Windows) and two nginx (Linux) are used as application servers. HTTP mode