Soft Wrapping Performance Limits in GNU nano 2.2+

Goal: Determine the point at which GNU nano’s soft wrapping feature begins to produce noticeable interaction latency when editing extremely long lines.

Constraints: The feature is available from version 2.2 onward, does not modify the file, and its cost depends on line length, terminal width, and CPU speed; no empirical threshold is documented.

Uncertainty: While anecdotal reports mention lag on files larger than several megabytes, the exact line length or file size at which the delay becomes perceptible, and how it scales with window resizing, remains unspecified.

Questions: At what approximate line length does soft wrapping introduce a perceptible scrolling delay on a typical modern processor? Does the latency increase linearly with line length beyond a certain threshold, or does it exhibit a step‑wise change? How does varying the terminal width affect the observed lag?