This doesn’t help you but it might help someone else. I use a similiar service by Kall8 to forward a US toll-free number to Taiwan. They offer local and toll-free numbers in US and parts of Europe and you can set up all kinds of routing rules depending on when they called, where they called from, etc.
while I worked for Fujitsu in Indonesia, we had similar setup, I remember calling Japan only by pressing local number, theres no reason why a move developed country like taiwan does not have similar service…
I have to search and inquire around first.