The only open issue we have with IPA is Windows clients not being directed to the Kerberos servers of the IPA realm.

We can solve this issue using domain_realm registry keys as mentioned on the mailing list before.

But is there any different method to accomplish this?

As far as I know/read, Windows clients only use SRV DNS records (and can fail back to NetBIOS-based discovery) to locate domain services, not TXT records.
As IETF Kerberos Clarification drafts recommend against using (then) unsecured DNS for domain_realm mappings.
So TXT DNS domain_realm mappings are also not an option.

Sincerely 
Pieter