RPG Architect!!
Amazing, I didn't know about this app. I tried the early access version today. To be honest, I feel it has much more potential than RPG Maker UNTE! I was surprised that I can switch to 3D view with just one button! (Though I'm not sure if I can create tiles that work well in 3D...) The asset specifications seem quite flexible, so at least the assets from my previously released MEGA FANTASY series should work as is! For future assets, I'll include ones that are designed with RPG Architect in mind. Thank you for the information!
By the way, in return, let me introduce you to WOLF RPG Editor. It might not be well-known overseas. It's quite a famous 2D-specialized game engine in Japan, and interestingly, it has an English version too. Despite being called an "RPG Editor," it's actually a versatile tool that can create games of any genre except 3D.