Tom, don’t quit. Stay with us. You are an important mapper in the Thai community.
There are terribly many issues with the map. Still, I’ll use OpenStreetMap during my next holidays in Thailand. I’ll show the edits by the Facebook team in a different style (their ways have an ‘import=yes’ tag, so I can do that). Also other regions (e.g. Taiwan) have big issues, even without FB’s imports.
Keep working together with us, and let us try to improve things.