there are multiple firmware downloads available
i’am using a “Pixhawk 4 Mini” for a Fixed Wing (Delta) Plane
so what is the right/best option for that?
or what are the main differences or advantages/disadvantages between them?
The difference can be seen in the board cmake files:
So it looks like the fixedwing build is stripped down for less flash usage but does not contain anything more than the default.
This means that you can use either one, however, I don’t think the specific builds such as the fixedwing ones are used or tested yet, so I would recommend to just stick with the default one. It should not have any drawbacks at runtime.