While I do stay away from all polyquats, the ones that I know give me problems are 4, 7 and 10. It may be that you want to target those. If you still have issues, then stay away from all of them.

Not sure what BCB means. Something you may want to try to do is get more frequent trims. Maybe do a few inches to get rid of the worst of the tangles and then go every two or three months and take off an inch, or so. That might help keep the ends from tangling.
3a (Corkicelli), highlighted, fine, low porosity
modified CG, since April '07
CG since 3/11/08

SE PA

HGs: Anything Sevi; Curly Kinks Satin Roots, Curlycue ReNew and Coil Jam; homemade FSG and okra gel; soap bars; UFD Curly Magic; Botanical Spirits Jellies, CJ Repair Me, Marie Dean Leave Ins and Curl Creams