I am not in rootworm country so efficacy of bifenthrin in furrow for rootworms is better left to someone else.  As for bifenthrin through a dosatron, I have done this for years and never had a problem with any generic that I have used.  I do dilute it with water to make a 50:50 mix in the dosatron.  I think that the EC formulations need to be diluted before injecting into fertilizers to reduce compatibility issues.