啥时候支持sparse模型?

[starkeisntein]

Limitations and Future Plans
BytePS does not support pure CPU training for now. One reason is that the cheap PS assumption of BytePS do not hold for CPU training. Consequently, you need CUDA and NCCL to build and run BytePS.

We would like to have below features, and there is no fundamental difficulty to implement them in BytePS architecture. However, they are not implemented yet:

Sparse model training
Fault-tolerance
Straggler-mitigation

readme这里所写的计划，Sparse model training，应该是指广告推荐模型那类模型吧？这一点计划什么支持？