Choosing the best "base_log" and "level" parameters in KeySwitch

Hello there,

I am quite interested in Key Switching feature. In order to maintain the best ratio between computational cost and accuracy in the result, I was wondering what criteria to follow when choosing the “base_log” and “level” parameters of the Key Switch method. I am trying some “random” combinations, but I always lose some bits of precision. I guess this is due to the precision-bits chosen in the encoder.
Following the recommendations of the documentation, it is advisable to keep the “level” parameter low.

Hope someone can help me. Thank you for your help and time.