Many other distros almost work out of the box (as in they boot and run without any modifications). The custom kernel patches you mentioned address mainly non-critical bugs such as a bug where the Realtek r8127 stops working after a reboot (but it works if you turn it off and on again) [1] [2]. I'd consider it in a way better state than trying to run other Linux distros on certain device tree-based devices like, say, Qualcomm Snapdragon machines. The regular NVIDIA drivers with the open source kernel modules work just fine. Talos Linux supports DGX Spark since version 1.12 [3]. I also know of people using Fedora and nixOS successfully.

[1] https://github.com/NVIDIA/NV-Kernels/compare/ea55925ab430f1e...

[2] https://forums.developer.nvidia.com/t/realtek-r8127-ethernet...

[3] https://github.com/siderolabs/talos/issues/12170