One night I went to a bar where some buddies were playing and did an experiment, fully intending that the end product was not usable except as an experiment... I would do things like run X/Y for 2 minutes, then try to switch it to DINa, then after 2 minutes of that, go to ORTF or NOS or DIN, or whatever. Keep notes of what you are doing so when you listen to it at home you will know. The result of that test was that I like NOS with my Nak300s. Another time I took 3 Naks with my MX100 mixer, 2 cards and an Omni mix, and tried different amounts of Omni... again keeping track of where I had the knobs set. To me that "wasted" evening was a great learning experience.
At Wanee last week I ran split Omnis for the first time... on one of the opening acts which I wasn't too concerned about. Then I switched back to "my old standby" mode for the rest of the show. Later I listened to the results. I like the sound of the split omnis, and will try it again sometime.
The point.... experiment and decide for yourself. Yes, these setup patterns have some theory behind them, but it's YOUR tape. Do what sounds good to you.