Were the file cut ribs made for anti-glare or for heat distortion rising from hot barrels.....as a predecessor of the raised vent rib...?

We know that Italian, American, German, Spainish and French makers commonly file cut (and drill turned) their ribs, whether swamped or flat........So why didn't the English...?

The best question would then be do the English file cut the ribs on NEW PRODUCTION double guns today.......?

Best,

Doug