I was uploading the icons for the neon stoves goals when I noticed that when you complete goal 1 the icon displays a number 2, for goal 2 a number 4, for goal 3 a number 6... So how should I name the pictures? I just uploaded one in case I did it wrong. As an example, this one is the icon for goal 1:
I haven't started the goal set yet cause I've been too busy to play CW right now. Until I start working on the goals I'll be able to answer your question better. I'm leaving for work in a few minutes so I won't get started on it until I get home.
Part 1 shows 2, Part 2 shows 4, Part 3 shows 6, Part 4 shows 8 and Part 5 shows 10. I think it is because they have only 13 parts to each of the upgrades and they like having 15 for an ultra stove, so giving 2 per part of the first unlocking stages makes 13 + 2 = 15 (if that makes sense).
I believe they meant to do two stages per stove release, much like the Ultra Stove Mega Goals, but changed their minds at the last minute. Hence why each stove release is considered an even goal release number, while the individual stove goals are correct.