you might try send the blood sample to some lab outside US, the test should not be expensive at all
it looks like in US they want you on antivirals for life and not check how to eradicate hbsagwhich is equal to eradicate hbv
as you can easily understand it makes no sense to cure hbv without checking if therapy is lowering it
the test hbvdna but that's useless for eradication, hbvdna is also very expensive while hbsg quant is extremely cheap, about 7euro in italy or free by health care (maybe 50euro in some labs, not more)