Hello @lua40927.
Those are the only events which trigger the interrupts. However, you can configure the receive buffer size to meet your specific requirements, as shown in the below image:

I recommend to trying the "Example S32K312 UART Transmit & Receive Using Interrupt DS3.5 RTD300" to familiarize yourself with the UART driver and APIs, which are useful to configure the Rx buffer to trigger the Rx_Full event with one character and access to the configured callback. Also, please refer to de S32K3XX Reference Manual Rev. 9 for more information about the LPUART module.
Please let me know if this was helpful.
- RomanVR.
Best Regards!