Even now, with a complicated crafting recipe, some people manage to assemble their Kerfur-O in two in-game days. Making the crafting more complicated should have stopped this.
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Honestly, making it any harder isn't really good for anyone at this point. You have to remember that there are more casual players (like me) who already take a while to get Kerfur-O even pre-recipe change.
If people still can and want to speedrun getting it even now, good for them, they can play how they want. I don't think making the recipe even harder would stop them anyway, so making it harder would just be harming the casual players and not actually deterring kerfur speedrunners.