Solar Orb + Unleash + Overabundance vs. Orb of Storms

Orb of Storms when used with Unleash and Overabundance spawns two overlapping orbs, verifiable by recasting without full Unleash stacks.

Solar Orb does not function in this way, and instead can only be cast one at a time.

I do not understand why the interactions should be different from each other as the supports are used with similar skills.

I haven't been able to find an answer to this... But, Flame Wall does summon 10 SRS on Unleash. Could they be stacked on top of each other? I like staggering Solar Orb slightly so the pulses are happening out of sync. Don't think Unleash makes that happen, unfortunately. Let me know if you've discovered anything special for Solar Orb. I just killed the Count with only Solar Orb in SSF. I do have a build that uses Flameblast exclusively (Solar Orb). I wonder if Solar Orb can accomplish it as well.