JFX_MultiChannelMerge

• One node to merge all alphas

This multiChannelMerge node act like a common merge node but for the alphas. This is actually a group node where mergeNodes are created inside. You can add as many inputs as you want and you have access to all operation a normal channelMerge would give.
I chose to create or delete inputs dynamically by pressing buttons rather than using heavy callbacks.