Yep, thats exactly what I did. Its finished. 75 reactions. Its 15 materials and 5 items. The dye you have to add with stockpile setting if you want, otherwise it just accepts any dye.
The product is not exactly like a "real" dyed item, but close enough. It says "is decorated with plump helmet dye" and not "is purple with plump helmet dye". The reaction also uses up stacks completely, which is usually 5 dye. So if you have a bag with 5 dye, the vanilla reaction uses 1 and keeps 4, but my reaction uses 5 and leaves 0. If a bag contains several dye stacks, it will use all of them, but also apply all of them. In the example screenshot I used a bag with 2x5 plump helmet dye, thats why the item is decorated twice with it. All in all it works, but isnt as nice as I had hoped.
On the other hand, ALL megabeasts have a specific itemcorpse now which can be butchered in the Slaughterhouse. All megabeasts give a trophy and a greater soul, give a heart, and depending on body composition give 60 meat, 50 boulders or 25 bars.
And, best of all, you can use the soul either to make one skill legendary, OR reanimate the megabeast. So you kill a mountain giant, then use his trophy (mountain giant skull) and the greater soul to reanimate a friendly mountain giant. You just need a Changeling as a base creature.
The only problem I found so far is that you can kill it all over again, get the meat/heart, then reanimate it again, and so on... but it costs a changeling per reaction. Dont know if I should stop that behavior, so that you can only reanimate them once or not.
Say... does a ColossusForge as an upgrade to the GolemForge sound reasonable? ^^