4 ohm tap sounds better to me in my system as well.
I use triode mode for certain styles of music(acoustic guitar, vocal oriented) and UL for other (more complex).
Personally I don’t go by graphs, I go by what my ears tell me. For me the stock Chinese tubes in the center slots were my issue with my amp. (Dialogue Premium Integrated)
Most importantly I am glad your enjoying what you hear now.
I use triode mode for certain styles of music(acoustic guitar, vocal oriented) and UL for other (more complex).
Personally I don’t go by graphs, I go by what my ears tell me. For me the stock Chinese tubes in the center slots were my issue with my amp. (Dialogue Premium Integrated)
Most importantly I am glad your enjoying what you hear now.