Quaere verum. I got a ticket for speeding and told the guy I was in hurry. He said: "I perfectly understand and I will write a ticket as soon as I can." This is the highest level of professional attitude.
I'm switching to 12 min base frame from my previous 15 min base frame for the same reason I use 22 ema vs. the more common 20 ema. My tune up chart scale is still 5 min but I'll be experimenting with 4 min. What difference does it make? It's a subtly different view.