I used to use 28ga by choice for MTL but just found 26ga that much easier to work with so actually 27ga (middle of the road) is perfect for me, I wish all wire types for vaping were regularly found in gauge 27!Fair comment ... You have embarked on a fairly long term test, however it seems to be showing promise.
As to the odd gauge sizes ... Your guess is as good as mine ... I have noticed some wire suppliers quoting rounded decimal too