> Issue 2:
Seems it doesn’t occur initially.
The more text you type in the current tab, the slower it goes. While either of the other three options works fine.
Several lines would be enough to see the obvious slowdown.
Later the delay could be more than 10 seconds. And see the CPU usage.
(The default dictionary is used.)

Issue A:
Disable and enable WordComplete.
Type “s”. The list shows the candidates instantly and stably (without any flicker).
Delete and type “s” again.
** The list flickers. (Say it in slow motion: blink-blaaank-show.)
I think this still needs to be optimized.

Issue B:
Open a new tab. Type something. WordComplete works.
Detach the tab. Type something.
** WordComplete does not work, till you disable and enable it again, or use “Show Candidates Manually” command once.

Issue C:
When both a (snippet/ActiveString) tooltip and the WordComplete candidate list show simultaneously, sometimes the list dodges the tooltip, but sometimes the tooltip covers the list.
Can this be optimized?

Suggestion C1:
I think “Show Candidates Manually” command could be a toggle switch. So one can close the candidate list via this shortcut key.
Currently, when both a tooltip and the WordComplete candidate list show simultaneously, Esc key closes the tooltip first.

Suggestion C2:
Should also be able to temporarily close the ActiveString tooltip by using Esc key.

> Suggestion 2:
The Reset button is only displayed for English and Japanese language?

> Suggestion 3:
“…” button (in Dictionaries page) is not working properly.
When the “Dictionary File” box is empty, or when the path is unavailable/invalid:
Click “…”. Select a file. Open.
** See the result in the “Dictionary File” box.