FWIW, '88 I dropped by the Gazelle home office/shop in Dieren NL ..at the time they were building 531 race frames in batches .

I was only shown the low production shop , on the quick tour, wouldn't call it cold alignment ..

the main triangles , lugged, were brazed on torch array jigs , then moved to a 'push until the indicator light comes on'
alignment Jug , then .. they were left to cool..