About the RK3588 family I see that different vendors implement also the RK3588S and the more recent RK3588S2 and it seems that the difference from RK3588 is about hardware support.
Will the DeGirum/RKNN runtime work for RK3588S2 (S2) or there are also limitations in terms of NPU?
In terms of NPU, all those non-S/S/S2 flavors are the same. Our runtime will run identically on all of them using the same models. The difference would be if you use other chips like RK3586 or RK3566 - they will require different models (models are compiled on per CPU model basis).