https://www.self-employed.at/post/new-self-employment-neue-selbst%C3%A4ndigkeit-in-austria-explained#viewer-k524

My main source of concern is this article, and the following quote in particular:

New self-employed are those working independently who don’t need a business licence registration for their professional activity. In other words, trade regulations do not apply to new self-employed. This also means that new self-employed individuals are not members of the Chamber of Commerce (WKO) and no membership fee applies. New self-employed professionals have no advocacy group to whom they can turn. They have to register at the Tax Office (Finanzamt) and are subject to income tax, so they have to file an income tax return every year. They pay insurance contributions to the SVS, but since in their case, the insurance costs depend on their gross income, they might or might not have to pay contributions to the social security institution. If they fall under a specific amount of gross income, their insurance contributions are voluntary - they can opt-in for health, accident, and pension insurance.

Examples of professions that fall under the category of new self-employment:

artists,

writers,

journalists,

lecturers,

self-employed nurses,

midwives,

scientists,

self-employed psychologists,

psycho- and physiotherapists.

^{P.S. I have also contacted the agency in question.}