This is not what I have noticed. I have actually been testing this since the start of my diet.

What I heared and agree with is that they don't cause a sudden spike in your blood sugar, so they don't cause craving like breads do, but they still cause your blood sugar to go up steadily. Whatever throws you out of ketosis is the actual amount of blood sugar not how fast it changes.

Fortunately, they don't get absorbed 100%. The absorbtion rate is not the same for all of them. I have noticed that Erythritol and inulin are the only two types which seem to have minimum effect on my ketosis state. Later I read that the absorbtion rate of Erythritol is about 5% while the absorbtion rates of sorbitol, mannitol and maltitol are above 50%. This explained it.