Is there a faster way to insert text at cursor in AppleScript than "keystroke"?
Yes.

User @jackjr300 has devised an ideal solution to this question here:


Is it possible to keystroke special characters in AppleScript?


This solution works system-wide and does not affect the clipboard.

The provided TypeCharacters Objective-C file is significantly (i.e., exponentially) faster at typing text than AppleScript's native keystroke command.