I would think the amp would be more consistent though? Your kind of making me think that any annealer is just as good then......
https://www.ampannealing.com/instructions/
FWIW
This gives you an idea of what the sensitivity of using the average case weight would mean and how much hardness value variation there is with differences in the resulting code steps. You are able to change code values yourself based on your preferred feedback method, i.e. hardness value or seating force. You can always just run them without making adjustment changes unless you want to.
I'm not telling you what to buy, but I am suggesting that if you go the flame route, and you are being picky, then you also need to be skilled at setting your process such that you can control your hardness value as tight as the AMP.
In an industrial setting when a flame is used, the process controls include very good flame controls, long steady state large batch runs, and the benefit of a laboratory with hardness machines for flame setting feedback. If and unless you are meticulous with your flame setting and timing, and are prepared to experiment with your own feedback, then the easy button is to just use an AMP. It is possible to get this right on your own with a flame, but then the results are in your hands.
Remember, in a gross sense the grip on the bullet is a F=mu x N relationship.
The hardness value per se is directly tied to the modulus and yield strength of the brass, or in that gross relationship, the "N" term.
We are discussing annealing choices in some detail, but don't forget that the other side of that equation is the friction coefficient and also just as important to control. YMMV
