@Christopher **********
Where did you find that definition of "special"?
I did not see it anywhere else, so I think it is just your opinion.
In MfA documentation you can read the special purposes of stay and the extra requirements compared with other tourist visa, not that it permits you to perform remote work, which also is not true for all types of DTV.
The medical purposes you mention can make you eligible for a DTV visa, but can also be done without any visa at all, so what is your point?
A DTV is issued for a special purpose of visit, and IO can check at any entry if your purpose of visit matches your visa.
Most times they will not check, but they just can do so and when it not matches they can deny entry, up to you if you want to take that risk, but I guess you take the risk and trust bribing the officer will work.
P.S. Did you ever get a document with terms and conditions with your visa?
You just are expected to have knowledge of Immigratiion rules.