[ Request ] add option to use the old version of the simple scheduler ( with Stable Cascade )

_( I commented about this in the Stable Cascade testing issue, but it's very long now, so opened this as a separate issue, with the more relevant images. )_

After this commit: https://github.com/comfyanonymous/ComfyUI/commit/c6b7a157ed30eb2dd59891ba465b7b5be97a687a , the images are very different, when changing the [ shift ] value, in the [ ModelSamplingStableCascade ] node

With the default shift value ( 2.00 ) the images are basically the same, but with shift = 3.00 changes are very noticeable.
I changed the code, to revert the commit, to make sure it was this, and created an image to compare.

I like both versions of these images. With and without this commit.
Adding an option to use both versions of the simple scheduler, would be a very nice way to get more variations.
This level of change is comparable to changing other options, like the scheduler or sampler, so I think adding a new option would be justified.

Also, note that changing the shift value is not enough to compensate for these changes.
If I use the shift value for 3.2 instead of 3.0, I can get the old face expression back, but there is no braid, and the dress is different.
And with the 3.2 value, the iris is worse ( less round ).

shift = 2.0 ( default )

shift = 3.0

shift = 3.0 - changed code to revert the scheduling commit

shift = 3.2