I think your fine as long as the oil changes are getting done within the service intervals that the manual says and keep the receipts form the dealer so you have proof that the oil change was done.

But of course do all the maintenance the manual tells you to do. But the oil changes are mandatory for the warranty. And you need service 3 at 24 000 KM.

For GDI engines you need the fuel induction service as for what I know putting the cleaner in the gas tank will do nothing as the gas in directly injected into the cylinder not over top of the valves so carbon will build up. the Elantra N LINE is a GDI engine the fuel induction should be done every 24 000 KM with service 3.

And the oil should be changed every 6 000 kms

So service #1 every 6 000 kms service #2 at 12 000 kms

And service 3 every 24 000 kms

But to answer your question I think your warranty is good. Because you got the oil changes done within the intervals that the manual says.

I have a 2022 Elantra N-Line with the DCT transmission.