This is indeed interesting, the main benefit the source routing has is that the whole routing between (router) devices is determined by deCONZ and doesn’t rely on what the devices may think could be a good route.
Each message send from the coordinator contains the whole routing path and routers just forward it “blindly” without having to know or find a route. In my experience the larger or complicated the networks are the more beneficial source routing becomes. And then there is also the problem that Osram devices tend to propagate sub optimal routing information, which can be worked around with application level source routing.
Question: can source routing values be too aggressive and cause problems? If I set the minimum LQI to the lowest value (60) and increased the hops a bit, can that cause more issues than it would solve?
The defaults are a good starting point, the values are a bit trial and error to get right as this depends on the network. Usually if the GUI shows a lot of strong links like above LQI 150 I tend to set it to the rough average of the strong links. But some networks are a bit weaker here it’s okay to lower the minimum LQI value otherwise not many source routes would be created.
If the value is quite low from the beginning it’s still ok, the algorithm discards routes that don’t work out over time and still aims to get the strong routes before weak ones.