Ned, running at FC/CYA ratio for regular treatment when using a sequestrant shouldn't be a problem if you're adequately dosed on sequestrant. Its only
SLAM Process levels you'd need to worry about restaining.
If the MM isn't keeping staining in check with full dose maintained correctly, then perhaps your metal concentration is too high, in which case you'd need to dose more or consider a partial water change, or perhaps an end-of-season oxidization and filtering removal remediation. Every metal case is a bit different and I don't recall your specifics at the moment.
But in general, its always a Sophie's choice in the world of metals
But you've got to maintain TFP [fc/cya] levels.
Like Matt says, we don't really know if removing spent phosphates from heavily sequestered water is worth the trouble or not, and I am going to experiment with that this coming year to see if it makes a difference, starting in a week or two with an alum floc experiment, followed by small weekly doses of lanthanum chloride while operating in winter.
But we do know that HEDP is the most effective sequestrant, pain in the butt or not