In WebGL Mode, RMMV can occur the error related with MAX_TEXTURE_SIZE when using 16K texture. and then In battle, If you were used this plugin, you could use the texture bigger than 16K (2^14) size. But, It can be slow with the animation speed when using 2d context. So this plugin automatically provides toggle options to enable the canvas by checking texture size.
That issue is the same as above screenshots. When a state icon has 0 index, It shows up the black quadrangle over all monster's head. It has any error related the texture size. But it will be possible to show up for the state icon that is properly painted if you are using default bitmap the same as 2d context.
You might want to create a very large texture by adding this plugin. But you will not have to include this plugin to your project if you want to implement a fast animation.