While the physical hardware to self program is readily available, the manufacturer’s software is not.
The software is proprietary and most manufacturers will not release the software except to one of their dealers (dispensers).
It is conceivable that a manufacturer might get tough about unauthorized use of their software and take some legal steps to prevent use by non-dealers.
Discussions of illegal sources of software, could precipitate nasty legal action to close down forums carrying such discussions. Some manufacturers may go to great lengths to protect their stuff that cost them a bundle to develop.
Personally, I find the mfg’s short sighted in their protective stance, because their software has only one use, that is, to program their aids which they made a profit on. Ed