There should be a valve to bypass the softener (for maintenance, etc.). I don’t know what yours might look like, but mine is directly in front of the softener tank. It might be labeled on/off, but you can also do “in between”, so a bit of untreated water bypasses the softener.

Allowing a little bit of hardness to bypass makes the water less slimy feeling, while still being good and soft. Fully soft water is a bit undesirable, just like hard water. It can be corrosive over time, plus you use more salt with the softener on “full blast”.

It takes some time to find a good setting. It’s just a trial and error type of thing.

Here’s some info: https://www.madsewer.org/news-resources/blog/soften-water-with-less-salt-using-blending-valves/