I’m a medical marijuana patient and sublinguals do take up a portion of dispensary shelf space and I personally use them. However, before compassionate use cannabis was legal in my state, during total prohibition, I did not even consider that as a method of consumption.
You could do a very simple alcohol extraction of psilocybin and end up with a cheap, dose regulated method of consumption. But just like some people buy their cannabis tinctures in dispensaries, I’m sure people would also prefer the convenience of purchasing that extraction with a brand behind it.
If there was a legal framework for this to be available, yes I would experiment with a sublingual product.