There is a little bit of information on homeschooling elsewhere on the forum that might be relevant. I was actually looking into whether we could use a charter program from our home state in the US, where we would remain residents (have an address and pay taxes). Optimistic on that front, and there would be no cost if we could swing it. Some charter programs even pay a small education fee to students, or so I have been told. The one I spoke with would give our student a laptop and send lab kits to our US address at the beginning of the term. We would have to return to our home state once a year for state testing.
There is a Facebook group called learn@home in Taiwan that might be helpful.