The powder is simply hardened and frozen but otherwise sticky like obtained in a dispensary the moment it thaws. It thaws really at about ambient room temp according to your own definition of solid or liquid. My personal stash is terpene free which allows the powder to stay frozen at room temp fairly long. However the moment it is sprinkled onto the tongue it again returns to hydrophobic and will not readily disolve in saliva. So what happens simply is you end up swallowing it and then dose that way. A big lump under the tongue will disolve but very slow like a glob of caramel but harder a bit. whether it is absorbed into the upper gi tract at that point or not is unknowable by me.
The problems with oral dosing are well known. Much medicine may be lost according to stomach contents and your ability that day stomach wise to digest. This is a problem with all medications ingested so devices like capsules and such that have a variable ability to time release medicine are used. D9 THC cannot be made to have a different melting point.
My goal has never been to develop any tech for oral administration. I have tested on myself many times oral dosing. It is not for me as it does not relieve the urge to medicate as quickly as vaping or otherwise inhaling. As for me the inhaling is very stealthy because my medicine is refined by me to remove all traces of odor really. I know with certainty what pure D9 smells like and can assert that the average Joe on the road would never equate the smell to cannabis but more a pleasant aroma therapy type odor with a hint of polymer evidence and generally fairly faint at that. It eliminates the need for odor control in the home and outside.
I think a huge part of the allure of oral ingestion is the stealth factor meaning no hassle of odors in the home or on the person and also the easy ability to take it on the road then for your journeys.