I discovered secret, that can save time in the run. If you use the bed in the kris house, you will be appear in the dark world. Is it allowed?

This is already known. Since this is a in-game feature, it is allowed to be used in runs. True Reset runs ban the use of this skip and the regular any% allows it.

Yes, atleast in any% runs, in True Reset any% you cannot use the bed [i think].