Yes, but what percentage of weight should be carried on that foundation: 0 to 100%?
You might ask your teacher the same question. If he/she is ok with you kicking up into a supported headstand, then they cannot be trusted to know. The risks of an improper headstand do outweigh the benefits, since the best of them, in your case, can be achieved otherwise, i.e., shoulderstand. Ask about half-headstand as well.
It's not about stacking your weight into your cervical spine. From dolphin position with your head placed on the floor, if you are not able to create and hold space between the floor and top of your head, then that's as far as you go. If you were to do a headstand on a single sheet of newspaper, I should be able to remove it without tearing it.
best to you dear,