Following up on the Multidot question:
I think I figured out a bit more where the issue is.
First, no multi-dotting enabled in Condition 15 of the default rotation. It just says:
Condition 16, for Moonfire, Moonfire reads:
The only change I made to Sunfire's condition 15 was to add the Multi-DoT count.
When I run Stellar Drift, the sim multi-dots with sunfire perfectly fine and gets 200% uptime on Sunfire even when the boss targets are split further than the range of Sunfire spread.
However, when I run Nature's Balance, since condition 15 doesn't include the extra bit about Targets in range of the caster but not in range of the sunfire spread mechanic, it never dots the second target with Sunfire even when the multi-dot condition is enabled.
I just deleted the nature's balance condition on Sunfire and the multi-dotting works and yields a dps increase. It doesn't excessively refresh sunfire either as it's still properly registering the Sunfire refresh from casting Solar Wrath.
With Shooting Stars, on 2 target sustained, multi-dotting with Sunfire when it can't spread because the targets are too separated is over a 3% increase. With BotA, multi-dotting with was still a significant increase even without the extra AP and Damage from shooting stars, coming in at 2.1%.
With Shooting Stars:
Default, 2 targets: 1.226m DPS
Multi-Dot with Sunfire, 2 targets: 1.267m DPS
Multi-DoT with Sunfire is 3.3% increase.
Default, 2 targets: 1.225m DPS
Multi-Dot with Sunfire, 2 targets: 1.250m DPS
Multi-DoT with Sunfire is a 2.1% increase.
Multi-DoTing with Sunfire also just better reflects what players do with the spell.
Last, when it comes to Stellar Flare, at least for 2 targets, it seems clear that it's only worth Multi-DoTing when the targets are in range of starfall.
When there are two sustained targets, Multi-DoTing with Sunfire and Stellar Flare is over a 5% increase in Multi-DoTing with just Sunfire