I find a difference between giving 10x2 second exposures and giving a single 20 second exposure with my Omega D2V enlarger fitted with a 75 watt Photocresenta bulb.
The intermittent exposure sequence includes 40 moments when the bulb is dim and red and non-actinic and 20 intervals when it is bright and actinic. But the difference is surprisingly (!) small. The resultant gelatin-silver photographs from either method can be eye-matched by a small change in room lighting. In practice the time adjustment I give to compensate for final dry-down (typically 8%) swallows the small intermittency effect.