I really need this, its the one thing im keeping other software around to do. BLENDER handles channels better than affinity photo. BLENDER! I work in VR but also do some graphic design and photography, and in every area of my work, i need this. From texturing for a games engine, quickly editing a mask while photo editing, removing noise, creating brushes, getting a clean transparency when reverse engineering a logo, Even my concept art composting has had to change, as i cant use unpremultiplied renders anymore, because i have no way of editing the alpha channel directly.
In my photography ive experimented with using red, green and blue lighting setups, and combining these separate photos to create different effects. that's just impossible in affinity photo right now.
.... its really starting to feel like i'm missing a key tool with no good work around.
And yes, there's some uses for the channels panel as it is, but it all feels like long-winded workarounds, when all we want is to be about to edit each channel no differently than we do the combined image.