Are there any other options besides the Osto Voytek for a carbon flatbar hardtail with all of the bikepacking type mounts?

If you want a fat bike the salsa beargrease has a bunch of mounts. It might even have more than the voytek. I wouldn’t categorize either as a hardtail since they’re 1) fat bikes and 2) handicapped by their q-factor. You could get a cutthroat and throw flat bars on it or get a woodsmoke on the used market.