The profile is Step sculpture 2 pretty close to cherry profile of gmk.
They are thick but not as thick as Enjoypbt keysets which are cherry profile caps.
But you have unlimited customization, being able to choose the dyesub color, i saw someone posting a chart of that here somewhere.
Taihao would look like trash compared to the 2 other keycap makers you've mentioned. (they are thin, they have flash(excess plastic), OEM profile, and the antibiosis texture is crap)
Varmilo is around 1.2 or 1.3 mm, I can't find my caliper now.
A little thiner than other good quality PBT caps(1.5mm).
It should be Cherry profile but I didn't compare them very carefully.
Maybe there's a little difference.
Tai-hao is not using the coat any more.
Unless you get old stock, but they've changed it for a while, it's should not be easy to get old stock.
Some of their keycaps use old box says it with coat, but actually they don't.
They just use old boxes.
They finally change their boxes design this year I think.
But indeed Tai-Hao has only around 1mm thickness.