I would like to debug a PIC32MK0512MCJ048 device via J-Link/JTAG. This device is not shown in the list of supported devices. Is it possible to choose an ohter one? Is it planned to support this device?
Yes, it is planned to support these. You may give it a try by selecting a PIC32MZ derivative with identical flash size. However, this is a shot into the blue with no guarantee.
It is planned to support the MK series as well. However, considering the current workload this is not likely to happen before mid. 2022.