I wonder about the effectiveness of Polyquat additions in high FC pool water. Typical a high FC will cause the polyquat polymer to become cleaved into shorter fragments. It's not clear that the effectiveness of the polyquat is degraded but the recommendation is to add the polyquat after the FC comes down to "normal" levels.

I'm not arguing with your methodology, just wondering if there's a better point at which to add the polyquat?