Instead of saying "I want minigames for crafting" or "I do not want to have any minigames in my crafting profession", let's think about an discuss, what it would need to make it good and acceptable for the majority of crafters. Then we may end on a set of requirements that'll make for an exciting crafting system, or we may end on a set of requirements that'll make it impossible to make such a crafting level good. But lets postpone this conclusion for the sake of an open minded discussion.
So, here are a couple of things I would expect from a crafting Layer:
1. No RNG!
Any skill needed for the crafting should be focussed around your knowledge of how to do something and your decisions to do something in a particular way. A crafters customers expect a certain product and RNG should not get in our way of crafting that product.
If there are any RNG elements in the system, they must be either opt-in, which means there must be another way of achieving the same thing without any RNG risk, or connected to aspects like "over-enchanting".
2. Accessibility
There should not be any requirement to match a certain rhythm or any other dexterity checks as they are not meaningful in terms of a crafting process. A mistake in thecrafting process must always be reversible (e.g. by adding a bit of a certain resource).
3. Theorycrafting
It's okay when there are different ways of achieving the same goal (e.g. using 3 units of a cheaper resource vs 1 unit of the more expensive resource or a combination of 2 cheaper resources). This can keep the "minigame" interesting or make it interesting again when new resources are introduced because then there may be new ways of creating existing items.
4. Explorability
I should always be able to explore all aspects of the crafting system without extra cost apart from the time we invest. Giving us a "Cancel" button that returns all used resources back to us would be enough for that.
5. Recipe books
Finding the best way of creating a certain item can be interesting, reproducing it over and over is tedious. So, whenever I craft an item in a certain way, I should be able to save that way to a recipe book. The space in my book can be limited if it means that I have to buy more pages or so from a scribe.
A good example for a crafting system that I think would work well in an MMO is PotionCraft. We discussed that
here
Is there another requirement I missed?