Currently Paste application outputs whole lines in previews. When content pasted is one very long line (e.g. 1MB oneliner) this not only slows down page download but also freezes browser in rendering. When content is highlighted this can freeze browser tab for 5+ minutes while rendering content of single preview (that is not visible to the user anyway, lines are not wrapped in preview).
It would be nice if Paste application would truncate long lines in previews.