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That sounds very plausible. Thanks for pointing out this.
PRs are welcome. I do not currently have the bandwidth to do MySensors development myself.

@monte first of all I like the idea of having a multi-purpose sensor which can embody different "personalities" on the fly. NodeManager came in exactly for the purpose of providing a simple to configure, modular firmware with a set of predefined sensor ready to use.

BUT this is defined at compilation time not at runtime as you are suggesting. Reason is simple: since there are 60+ ready-to-use sensors in NodeManager, accommodating everything especially in a small arduino is not feasible, also considering the dependencies some sensors bring in. I see usually up to 3-4 sensors can fit the flash, no more. But I expect in different environments the situation could be different or at least for a subset of those.

All of this to say I believe NodeManager is a good starting point for what you are intended to do since you already have modular code for a good number of sensors, hooks for the different phases of the lifecycle and a way for communicating with the node through a "service" channel if you need to send something and act upon it. So feel free to fork the project (preferred way) or start from there.
All of NodeManager's details can be found on https://github.com/mysensors/NodeManager
Thanks

@j54n1n at this time NodeManager can only handle interrupts through the designated pins and only one type of interrupt per pin. But feel free to submit a feature request on https://github.com/mysensors/NodeManager/issues and, if you have, any piece of code which may help in the implementation. Thanks

@kiesel Beware that I believe the 6 leg chip is I2C which is not supported. Only the 3 leg SWI variant is supported.

@kiesel It is a SOT23 if I remember correctly. There are only 3 pins, no pad underneath so soldering should be easy.
Perhaps the copper you see is part of a ground plane? It will not connect to the signing chip in any case.

For anyone interested in it, I've recently published an eGeoffrey app for Android. It is available on Google Play, just search for eGeoffrey and you find it. Of course you would need the so called egeoffrey-gateway accessible to have the app connecting to it and working correctly

@encrypt noise sensitivity could be temperature related if the radio runs "hot"

@encrypt 868 MHz is not unique so there could be interference. But yes, decouple the hell out of it. You cannot go overboard with decoupling so if you have the space, go for both electrolythic and ceramic caps. Perhaps even a tantal to try to catch as many frequencies as possible.
Antenna will also help a ton if it is properly matched.

@encrypt for sure, going pcb will give the radio supply a better power signal (just remember to not make the trace too thin).
But as you have had the rig operational for a long time, it might be worth checking other radio channels as well as perhaps some neighbor got some dirty rf toy or similar that mess with the rf environment.

@encrypt the only things that comes to my mind is that your rf environment has shifted slightly or the noise level of the supply to the radio has increased to cause intermittent failure in the transmissions.
You could try to switch channel for the radio and see if it helps? Or measure the stability of the power supply to the radio when the node(s) are communicating.