I suggested this idea when I discussed PPS with Ed and others on APC a couple of years ago, only to be scoffed at.
And I'm the closed minded one
Within the context of PPS, and not doing water changes, then perhaps such chemical removal of organics is wise at higher growth rates that greatly exceed the normal bacterial rates of decomposition.
We and anyone worth their salt knows that large frequent water changes will drive a system faster and cleaner, pearling more etc for pretty much the same reasons, so the idea, the notion of chemical removal is also based on that premise.
But some with apparently far less knowledge and understanding about leaching, decompstion and biogeochemistry seem not the think so, based of their claims, such observations you have seen do not exist according to their hypotheses.........
You can observe the same things you have seen, both with the AC or the PG or the large water change.
You can mix them, add them at various times.
I think you will start to see some issues with traces over time with AC, but perhaps PG will be okay.
Try it and see.
I just do a water change weekly rather than change the AC etc monthly , that takes care of it. PG can be used and less issues with traces from what's said.......
But a controlled study?
Few have done it, if anyone and I'd be awful, skeptical of the methods done if such a claim came forward
But I think on a more practical level, try the PG, and keep doing the weekly WC and see if you think over time, that it helps.
I will say this, it will not hurt using PG.
So that's not a bad thing.