Ways to do overlapping of computation and commucation.

Hello, I'm trying to use DeepEP and intergate it into Megatron (with this commit https://github.com/NVIDIA/Megatron-LM/commit/0d389f5e9935957b146c12b1dcdddc35cf9deb85), and accomplish overlapping of computation and commucation, I've noticed DeepEP is using previous_event and async_finish args in dispatch and combine methods to support the overlapping , whereas the FlexTokenDispatcher in that commit doesn't adopt any of them. For me, there are two ways to do that:
* modify FlexTokenDispatcher and pass args previous_event, async_finish etc. to make use of DeepEP's overlapping interface。
* keep FlexTokenDispatcher as it is, and manage the stream and event outside by myself before calling dispatch and combine under the context of torch.cuda.stream(), which means DeepEP's pevious_event, async_finish won't be used.

Can you guys give me some suggestions about the two ways in term of performance?