I think your ticks are off.
Assuming no spell speed (cause we're given to understand ticks and gcd will scale with it now? so it is the same relatively).
Previously you would do
[2.5] - Bio II apply
[5] - Miasma apply
[5.5] - Bio apply
[6+] - all 3 dots ticking
So we can generalize the amount of damage things do, by prorating the ticks till 6 seconds
Bio II does 3.5/3*35 = 40.83 pot
Miasma does 1/3*35 = 11.66 pot (ignoring miasma direct damage for now)
Bio does 0.5/3*40 = 6.66 pot
Total is roughly 59.16 pot
With the thingymajig, instead we get 2 full ticks of all 3 dots, for a total of (35+35+40)*2 = 220.
We also get 2 ruins for 380 total pot.
Subtracting the previous we get ~320 pot.
Even if miasma direct damage didn't apply we'd get 300 pot which is a wash.
Advantages:
1. Can reapply Bio during RS for a bigger boost than versus a buffed ruin (48 total vs 16 total bonus)
2. Saves us mana, though not necessarily that useful when you consider we Aetherflow all the mana back anyway, so not really a bonus.
3. Obviously good for add bane.
4. Quicker sflare application. Whether or not you precast this ends up saving you a bunch of gcds.
5. Aetherflow 10 sec quicker (since you don't need to wait for 3rd fester)
Disadvantages
1. We can't make fun of tri-disaster anymore for being useless.
2. Possibly not actually a dps gain - because as long as dots have full uptime, saving time applying dots ends up being a lower and lower actual dps increase.