While I play bottleneck on a couple of Dobros and blues harp on a bunch of Hohners, I find I do have a slant on the tuning thing.
I submit that standard tuning is only important when writen musical standards are important for ensembles. Any tunable stringed instrument can be tuned in hundreds of different ways but writen standardization allowed European musicians to create music that could be repeated in concert halls around the globe. The objective (before recorded music technology) was to be able to play the music the way the composer intended.
now that my European based musical training is long past and I'm older and into the bluEs I find as the Delta blues greats that the tuning depends on the range of the voice so the guitar should be tuned to allow the singer to sing without much effort. This applied to twelve string folk and blues singers as well as Delta slide six stringers who may have had trouble singing if their axe was tuned to "E Standard."
Now that I'm older, I really enjoy open G tuned down to open C#. I use thicker strings so that the tension is maintained and they don't begin to sound sloppy!!???
Go ahead tune down, tune up or what ever. Your guitar will probably tell you where it would like to be tuned and what to play, listen to it. :}
My humble opinion and probably mine and mine alone.