Visual artifacts when using cull_disabled and transparency

Godot Version



I have visual artifacts when attempting to render transparent objects with cull_disabled

Here is the simple shader I made to illustrate it the problem in the above image:

shader_type spatial;
render_mode cull_disabled, depth_draw_always;

void fragment() {
	ALBEDO = FRONT_FACING ? vec3(1.0, 0.0, 0.0) : vec3(0.0, 1.0, 0.0);
	ALPHA = 0.5;

It still happens when using the same color on both front and back faces but is less obvious. Am I just going about this the wrong way entirely? If want to make a material for empty bottle where you can also see the back side, how should I be going about it instead?