Two different things
A registered shareholder appears on the company's own share register. They typically hold voting rights, statutory information rights and a direct claim in a winding-up, as set out in company law and the company's constitution.
A unit holder holds an interest in a vehicle. Their rights come from the vehicle's constitutional documents, not from the underlying company. The vehicle sits between the investor and the asset.
What a unit holder generally does not get
No direct vote at the underlying company, no direct claim on its assets, and usually no direct line to its management or its board. Information typically arrives through the vehicle's manager, on the vehicle's timetable, in the format the issuer permits.
Unless the issuer explicitly approves direct registration and the law permits it, direct share ownership is not part of this concept.
Read the vehicle documents, not just the company story
Because rights flow from the vehicle, the vehicle's terms decide what you can actually do: how units are valued, whether they can be transferred, how decisions are made, what fees apply and how the vehicle can be wound up.
A compelling company story tells you nothing about the quality of the wrapper you are buying.