> similarity to a rebranded Sipeed NanoKVM

That NanoKVM is RISC-V, the JetKVM is ARM Cortex-A7. Unlikely to be a rebrand.

That said the UI looks somewhat similar so Sipeed might have aped the JetKVM software part (which is FOSS)

The NanoKVM-Pro uses a AX631 2xA53 1.5G, which can apparently also support the PiKVM software.

The JetKVM uses RockChip RV1106G3. =3