Hmmm, Agent as in 'connmanctl> agent on'?
Which distro are you using? On the RPIs, I do not believe that raspbian (whatever it is called now) has kernel support for iwd so I don't believe that it is a candidate for an investigation. I could be wrong, though and the current version might. I do have 2 laptops with Arch on them right now and can install something else on one of them. I find it strange that all Arch Linux installs fail in this test and would like to see if a different distro may behave differently. It would be preferable that it run on an RPi, but I could put it on the laptop...