Glow / Bloom Particle Shader [SOLVED]

The issue with the shader from that Stackoverflow answer is the alpha blending mode "Blend SrcAlpha OneMinusSrcAlpha" which is used in the traditional "particle alpha blended" shader. For "additive" blending result, you change the blend mode to either "Blend One One" or "Blend SrcAlpha One". Also preferably change "ZWrite On" to "ZWrite Off". Shader receives color from renderer component via the "COLOR" semantic (all-caps).

The following code is modified from the official Particles/Additive shader, hence the copyright comment in the beginning:

 // Unity built-in shader source. Copyright (c) 2016 Unity Technologies. MIT license (see license.txt)
 
 Shader "Particles/Additive Intensify" {
 Properties {
     _TintColor ("Tint Color", Color) = (0.5,0.5,0.5,0.5)
     _MainTex ("Particle Texture", 2D) = "white" {}
     _InvFade ("Soft Particles Factor", Range(0.01,3.0)) = 1.0
     _Glow ("Intensity", Range(0, 127)) = 1
 }
 
 Category {
     Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent" "PreviewType"="Plane" }
     Blend SrcAlpha One
     ColorMask RGB
     Cull Off Lighting Off ZWrite Off
     
     SubShader {
         Pass {
         
             CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag
             #pragma target 2.0
             #pragma multi_compile_particles
             #pragma multi_compile_fog
 
             #include "UnityCG.cginc"
 
             sampler2D _MainTex;
             fixed4 _TintColor;
             half _Glow;
             
             struct appdata_t {
                 float4 vertex : POSITION;
                 fixed4 color : COLOR;
                 float2 texcoord : TEXCOORD0;
                 UNITY_VERTEX_INPUT_INSTANCE_ID
             };
 
             struct v2f {
                 float4 vertex : SV_POSITION;
                 fixed4 color : COLOR;
                 float2 texcoord : TEXCOORD0;
                 UNITY_FOG_COORDS(1)
                 #ifdef SOFTPARTICLES_ON
                 float4 projPos : TEXCOORD2;
                 #endif
                 UNITY_VERTEX_OUTPUT_STEREO
             };
             
             float4 _MainTex_ST;
 
             v2f vert (appdata_t v)
             {
                 v2f o;
                 UNITY_SETUP_INSTANCE_ID(v);
                 UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
                 o.vertex = UnityObjectToClipPos(v.vertex);
                 #ifdef SOFTPARTICLES_ON
                 o.projPos = ComputeScreenPos (o.vertex);
                 COMPUTE_EYEDEPTH(o.projPos.z);
                 #endif
                 o.color = v.color * _TintColor;
                 o.color.rgb *= _Glow;
                 o.texcoord = TRANSFORM_TEX(v.texcoord,_MainTex);
                 UNITY_TRANSFER_FOG(o,o.vertex);
                 return o;
             }
 
             sampler2D_float _CameraDepthTexture;
             float _InvFade;
             
             fixed4 frag (v2f i) : SV_Target
             {
                 #ifdef SOFTPARTICLES_ON
                 float sceneZ = LinearEyeDepth (SAMPLE_DEPTH_TEXTURE_PROJ(_CameraDepthTexture, UNITY_PROJ_COORD(i.projPos)));
                 float partZ = i.projPos.z;
                 float fade = saturate (_InvFade * (sceneZ-partZ));
                 i.color.a *= fade;
                 #endif
                 
                 fixed4 col = 2.0f * i.color * tex2D(_MainTex, i.texcoord);
                 UNITY_APPLY_FOG_COLOR(i.fogCoord, col, fixed4(0,0,0,0)); // fog towards black due to our blend mode
                 return col;
             }
             ENDCG 
         }
     }    
 }
 }