I can recommend Maya.net for South East Asia
I've been a loyal Maya.net customer for years. There are many eSIM providers out there, but I've always had excellent internet connections with Maya.net on the phones of myself, my wife, and our two children. Even when I made a mistake by activating multiple plans on the same eSIM, Maya.net resolved the issue within just a few minutes. A special thanks to Daniela G. for the quick and professional support! I would definitely recommend Maya.net. I've used their service successfully in Thailand, Indonesia, Malaysia, and Singapore.