But Dissipation is at least a trade of categorically similar things -- periodic healing for resources that can be spent on healing, rather than mobility (instant-cast Broils) for said resource.
Your Rumination, at present, is going to be little more than a trap, as saving 1.5 seconds of cast-time on a Broil is never going to be worth more than an Aetherflow stack. So you end up sacrificing two buttons -- one a trap, one a CD -- just to effectively grant Aetherflow per pet action cast. Given that we end up with effectively a non-decision, what is the point of those two extra hoops, as opposed to just allowing us to bank to 5 stacks of AF and having pet actions each grant an AF stack (assuming we even needed more AF, given that --because of our pet-- we already have a pretty combined damage-and-healing curve).
I'd argue that Dissipation should be slightly more worth using for curative purposes and faintly more usable generally; but, while those largest impacts to be had there would be on the fight designs themselves, that still leaves a lot of tuning levers in the skill's design. And that retuning, for it to better allow for the gameplay decisions it was originally intended for, does not require that we sacrifice choice in favor of free bonus resources we have to cycle through another CD in alignment with yet another CD, etc.
For instance, I'd argue that Dissipation should have a shorter duration and a more immediately usable effect towards shielding (as opposed to the whopping 30 seconds of a meager 20% healing buff) as to make it more viable for emergency or cheese heals.
Even if we needed to heal 100% of the time (we never do) and thereafter the pet would make up less than 20% of our healing throughput, we'd never drop the pet just to make up for that through our own GCD casts; we'd do it only for the immediacy and the effect on our shielding. So have the healing buff start higher, but fade with time (or casts made). Perhaps pair it with increases casting speed on Adlo and Succor. Whatever makes it useful more often, in the encounters/environments we want to push towards, for more than just better milking a raid window (though I am in no hurry to get rid of that capacity so long as it doesn't overwhelm our other needs or uses for Dissipation).