>>The bear case is that third-party and government payers don't think TAF-based regimens are worth a large premium price for most HIV patients
I believe one has to put on a political hat here to think about this. My take is the chances that insurers deny HIV patients the objectively better drug is close to zero. They can't even do step therapy, because the superiority relates to long-term safety, not to immediate tolerability or efficacy.
Further, not talking about a budget-buster like HCV. The savings vs. potential hassle and bad publicity are just not there in my view.