Spectre: what is the purpose of the "trannoisemethod" parameter?

Hi! I noticed there exist a Spectre parameter for the transient noise called "trannoisemethod", with possible values "default" and "adaptive".I have a few question regarding it:

• What are the differences between these modes?
• Does it affect somehow the accuracy vs. simulation time tradeoff?
• Is the noisefmax parameter taken into account differently between these two modes?

"spectre -h tran" only hints to an "adaptive noise step control", and this parameter doesn't seem to be further discussed in the documentation:

93      trannoisemethod=default
                          use this option to enable the adaptive noise step control. Possible values are default and adaptive.

Thanks in advance for any help!

Jorge.

P.S. I'm using Spectre sub-version 21.1.0.546.isr13