While one box with one developer might be enough to get something sort of working, to actually support a device properly several developers will need to have the device. Some support from the manufacturer of a device also goes a long way to enabling proper support for a device. Especially when some of these devices represent a brand new device to the project and not a yet another clone of something we already support.
Different developers work on different parts of CoreELEC, so support for some features would suffer if there is only one developer with the device. There are also situations where because this is something we do in our spare time that relying on only one developer with the device might mean long delays in fixing problems or adding new features for a device if that one developer has unexpected real world commitments eat up all their spare time.
Since we would like all our users to have the same experience and same level of support, and none of us like releasing code that we can’t properly test. Limiting official support to devices several of us actually have seems like the best way to achieve this.
We have had numerous difficulties in supporting some s905/s912 devices because of the previous approach taken to supporting them. It’s preferred that we don’t repeat some of the same problems from the past with the newer devices.