I don't use 5.2 anymore, but adding that product is not causing your astringency problems - so removing it will not fix it - so if you want to leave it in for now, no problem. You might loose some heat between the kettle and grain, but I'm sure it's not 40 degrees worth (212F to 170F). Heat to maybe 175F and check the temperature at the surface during the sparge. If it's high or low you can adjust next time, but try to keep it at or under 170F.