Yes they do include a generous collection of hardware. Unfortunately a) I asked and was told they were post mount and b) the calipers are using an 70mm spacing that looks like post mount but uses M5 bolts like flat mount. Something I read tonight suggested that this is one flat mount standard (the ones on my road bike are much narrower at 30something mm) The included adapters are also 70mm rather than the post mount standard 74mm (seriously, who in the industry decided to invent a new flat standard 4mm different and using one size different bolts? ) I thought about drilling it out but there isn’t enough material in the right places. I also do not find anyone doing flat to post adapters for the 70mm flat variant.

And while you’re right about drop bar bikes being more likely to use flat mount, this is a gravel group set where post mount is not rare.

So, now I’m wondering what calipers might be compatible with the LTWOO levers. I know that early on they were bundling with other makers calipers, so I’m guessing the piston ratios are probably common. Maybe Shimano compatible since they went with mineral oil. If so, that would be great since apparently pretty much all Shimano calipers are compatible including across road and mountain groups.

Not sure about Ltwoo's electronic groupsets but I am running a GRX400 front caliper with my Ltwoo GRT groupset since the mounting brackets for their caliper were not compatible with my fork.