Good test, and not so good result. I found the same, the current glare is capable of producing flare, but not true glare. Even for very high glare power, the highlights stay rough with no transition.
Here is result from VFB+. The glare is very complicated to setup there for true realistic behaviour, because power and size is unrelated. It's also not real-time, but computed like the one from ArionFx, although not as good as Arion. But it's kind of middle ground, and you can see it produces strong glare before massive star appears.