The linked document has an older list of accessible activities to do in Maui given to us by one of our peer members. This list is based off of their own personal experiences; it has a section for half day adventures, full day adventures, as well as places to consider staying. You can use it as a starting point for your research, but keep in mind that some of the information may be outdated.
The website was created by locals and outlines transportation and hotel information, as well as accessible activities in the area. It is not updated regularly, so it is most useful as a starting point but you will still have to check to ensure the information is current.