I had my PLM working with 710, and about 20 insteon devices, about 40% of the time when I would restart the core which is where my PLM is connected, I would lose a device or two on the floor plan. I have looked through all of the ruby code to try and fix this problem, and also add support for the HVAC adapter and for the motion sensor. The time out errors are because the PLM cannot communicate with the device at that address. The chip inside the PLM that sends and receives commands form your power lines is about 75% as strong as the chips all other insteon devices. So even though one device commutates perfectly with another device, It might not be getting the signal to the PLM. I fix this problem in my network, and now it works 100% of the time and even the response time on sending commands is faster. A few ways you can fix this problem.
1) Access Points should be located on the 1st receptacle on the line, As close as you can get it to the actual breaker box(this fixed my problem), and make sure one on is on each phase of your power.
2) Do not plug the PLM into a surge protector.
3) It would be ideal to have the PLM as close to the breaker box as possible.
4) Move the PLM to a different line that does not have lots of electronics on it.
After you get the communication problem fixed you should not see the timeout error any more.
I did look at trying to update the driver to support more devices, and I got the HVAC half way working, but I kept running into the problem of not having any link management available. You can link every insteon device from the PLM and never have to go around and push the dumb button in for 10 seconds. I could not figure out a good way to accomplish device linking natively in LMCE, so I stopped working on the driver. I spent a lot of time looking around to see how others are handling insteon networks, and most of them have gone with ISY-99. It has a lot of advantages over using just the PLM. I just received it in the mail last week, and started working on a driver for it.
Hope this helps,