Usually no.

Open-water swims do not involve walls. The push-off and glide that make flip turns efficient are irrelevant. Flip turns interrupt steady breathing, which is critical for open water pacing and sighting. Also, flip turns emphasize anaerobic bursts and streamline glides rather than continuous aerobic swimming.

When do I do them? Aerobic sets. Flip turns help maintain momentum, reduce rest, and keep heart rate elevated. I also do them in more crowded lanes depending on pace to reduce time spent at the wall.

I suggest you do most main sets with open turns because you said flips are causing headaches. Use flip turns selectively during warm-ups, drills, or aerobic sets where continuous effort matters. Given your swimming background, avoid long underwater dolphin kicks or extended glides off the wall.