I have been annealing every firing for over a year now but those days are over for me. I am probably gonna get flamed from heck and back for this but if I had it to do over again I would not waste a dime on any annealing machine. Not a popular opinion I know but that is ok
I am not a metallurgist but from what I have read cold working affects the brass at the molecular level while the modulus of elasticity which would affect neck tension occurs at the atomic level
some reading I did that formed my opinion -
https://store.appliedballisticsllc.com/Modern_Advancements_in_Long_Range_Shooting_V_II_p/0008.htm
https://www.uni-ulm.de/fileadmin/website_uni_ulm/uzwr/mmsm/mmsm1-ws1314/mmsm1-handout-plasticity.pdf
https://www.thestructuralmadness.com/2014/02/ductility-and-elasticity.html
https://www2.estrellamountain.edu/faculty/farabee/BIOBK/BioBookCHEM1.html
http://www.virginia.edu/bohr/mse209/chapter6.htm
https://www.quora.com/Whats-the-difference-between-ductility-and-elasticity
The other reason I am skeptical at best on any benefit from annealing has to do with the lack of testing at the actual firing line. I can find dozens of lab tests that show how annealing realigns the crystalline structure of the brass but try and find one showing firing line testing where the velocity SD & ES or durability of the brass changes or in any way over the course of ten or twenty reloadings. The only actual firing line test I can find is a limited one by Bryan Litz in his Modern Advancements Vol II where he found no changes in performance after ten firings whether the brass was annealed every firing or never annealed.
I have my asbestos boxers on so feel free to flame away. However if you want to persuade me find me some real word testing where velocity SD's or brass life was affected in any way by annealing or lack thereof. Pretty pictures of cases cut in half and microscopic pics of brass crystals are all well and good but that tells me nothing about real world performance. I want to see some tests performed with a machine rest and documented by a reputable lab or a world class shooter who is willing to stake his rep on the results
When thinking about this you might consider that precision shooting with long brass life was happening long before anyone ever annealed a case at home. Some damn small groups were shot and brass was reloaded well past ten reloads prior to this century