it's not 12 hours day, on bad day (usually monday and friday) is 8-10 hours of actual work, on good days (which are very rare recently) 3-4 hours, but usually I work between 5-7 hours (with some gaps between) plus I have free weekends most of the time and maybe 10 days of Chinese holidays spread over year
If I worked as full time employee here in Europe, I would spend 9-10 hours in work each day including commuting but with lot of spare time just sitting/resting in work plus 5 weeks of paid vacation, but also my salary would be like 20-30% of what I have as self employed working from home, nobody can offer me what I have in this company, so I wanna bank on this while it's available, because I'm sure it won't last forever (though I had this attitude already years ago and I'm still doing it with more work)
my main (if not only) issue is lack of continous vacation, I was just asking in OP how to justify taking it under these circumstances, if you are willing to spend let's say 4000USD on short vacation and another 2-3000USD on lost income, if I didn't work in hotel room. I just can't justify completely stop working even without worrying to be replaced