Latency issues when transferring files（文件传输时的延迟问题）

When using the mouse to drag and drop files for transfer, after sending rz/rb/.. to the system, there will be a relatively large delay, and the transfer will not be started immediately. Is this delay time configurable? If not, can it be fixed?
（当使用鼠标拖拽文件进行传输时，向系统发送rz/rb/..之后，会有一个比较大延迟，而不会立即启动传输，此延时时间是否可配置？没有的话，是否可以修复？）

No file, test, or entry point is named. Start by reproducing a mouse drag-and-drop transfer and measuring the delay after sending rz/rb; trace the transfer-start path to determine whether the delay is configurable. Done means the delay is removed or its configuration is documented and verified.

Written by the indexing model from the issue text.