I downloaded rhino 7 evaluation and it seems like some commands typed won’t appear but do work, for example, I type in mergeallfaces and it won’t give a suggestion nor show up in the list but does work.

The MergeAllFaces command name has been changed to MergeAllCoplanarFaces for V7. In native Rhino V7 there is an internal alias so that the old command name still works, but maybe not in Rhino.Compute.