If I active outline plugin, it need over serval minutes !
If I turn off this plugin, it take just 48 seconds on my machine.

test same text file on my poor machin :
RJ TextEd v6.82 complete instant
PsPad v4.5.5 take 6 sec

Cound you test more lines (ex: 900000) to highlight the issue ?

I look forward to future optimization version,
thank you.