The delay seems to be introduced by some part of the software involved with holding the composition string before candidate selection.
This can be verified by entering several letters in quick succession, causing the output to be delayed, and then immediately pressing the return key. This will cause the output to appear immediately. In the smart pinyin method, immediately pressing 1 after the input will cause the first candidate to appear immediately.
The delay seems to be introduced by some part of the software involved with holding the composition string before candidate selection.
This can be verified by entering several letters in quick succession, causing the output to be delayed, and then immediately pressing the return key. This will cause the output to appear immediately. In the smart pinyin method, immediately pressing 1 after the input will cause the first candidate to appear immediately.