Hillclimb Race Pacing - Going out hard. A smart move?

In running I’ve been taught that a good disciplined race has negative splits. If I wanted to run 7:00 miles, I wouldn’t go out and run the first few at 6:45 pace…

However, in cycling, especially on long climbs, it seems this is effectively what most people do. Looking at Strava fly-bys, etc… it seems like a lot of folks do the last third of a big climb 30+ watts lower than the first third. Is this just a lack of pacing discipline, or could there actually be an advantage here?

Specifically, I’m planning for a race at the end of the month. 6.14 miles, 2500ft (sorry for the imperial units) - so about 40-45 minutes at 4W/kg. About 1/3rd of the way up, there are couple short flatter sections where speeds creep up into the high teens for up to maybe a minute. Ideally, I’d find a wheel through those sections and keep speed up while saving some precious energy. However, if I’m committed to my even-power pace from the start, I might not catch those wheels until near the top - potentially losing out on a benefit.

I’m always afraid of blowing up and not finishing well, so I am reluctant to go hard at the beginning. How much above my target power (275W) should I let myself go for the first third, if it would mean staying in a fast group through the flatter sections?

I won’t be in contention to place in any categories, so I don’t see any sort of relevant psychological benefits to gapping people behind me early on… I just want the fastest possible time I can hit.