Well I don’t agree on that tray icons wouldn’t matter. They are very useful. But either way, it would be good to have the option for these two very basic and important functionality. On the compile flags, that would even be better, as these modules wouldn’t be in the final binary / install anymore.
But I would be just happy if we could turn the modules off in the options, so the actual Thunderbird client is less cluttered, less possibilities of bugs affecting me and lighter on resources. Why not get rid of them entirely and make standalone applications? It would free some development resources too, for the core Thunderbird mail client.
Maybe switching to a lighter alternative is a good idea.