Tube amp and correct speaker connections.

I’ve had many different solid state amplifiers throughout the years but new to tube amplifiers. Recently purchased my first and like many, there is multiple speaker binding posts to handle different speaker loads. 16, 8 and 4 ohm. My speakers are a 6 ohm load. The manufacturer has suggested both connecting them to either the eight or the four ohm binding posts, depending on who I speak to. I feel like I should be connected to the 4 ohm posts knowing that my 6 ohm speakers are likely 4ohm or less at times. I’ve run the speakers on both posts and I don’t notice any difference between the two audibly. I’m just looking for some experienced opinions on this.