I would imagine Halfan is, as it is related to quinine. While it can still be found in African markets, it is no longer recommended, as there is now considerable cross-resistance to halofantrine and mefloquine, and Halfan has quite nasty side effects (including cardiotoxicity). I would never recommend taking it. Lariam is even nastier (neurotoxicity).
When I had resistant P. falciparum, before Halfan resistance back in the early 1990s, I had to take “toxic doses of quinine” as the doc put it. I went completely deaf from it for two weeks, but thankful my hearing gradually returned. Not everyone’s does. At that time, Halfan was reserved for the direst cases, for fear if used too often resistance would develop. Resistance developed anyway.
I was advised by State to take Larium as prophylaxis, but decided against it after researching it. Once in-country, I came across some Americans who took the Larium and were very sorry. By 2000, the Europeans had realized how dangerous Larium can be. Halfan is not pretty, either.
Chloroquine is still widely used in Africa, along with Fansidar, because mefloquine and Malrone are too expensive.
You are right that chloroquine resistance is widespread, but, as they say, “TIA” (this is Africa), lots of bad things or things that don’t make sense happen all the time.