Convergence mode means that you are not on the go.
When you are not on the go, what is the sence of having such functionality build in to carry around all the time instead of having an accessory docking station with cooling function.
Btw I was imagining an aluminium stand for Librem 5 out of a big block of aluminium precisely cut to fit Librem 5 and make a good contact. So virtually acting like a giant heat sink. Sometimes I put Librem 5 on a big steel pot to cool it down 
4 GB of RAM is a little too little nowadays. More RAM would open the topic of virtualization which is a huge thing for a security focussed device.
The thickness does not bother me. Realistically, Librem 5 will always need a huge battery.
NFC, RadioFM ect. all not essential functions useless for many users. Instead of built in such functions taking space, weight and costing money, I would prefer several USB-C ports so that one could plug in accessories in dongle format of own choice. So that you could use a RadioFM dongle. (Btw. I have never listened to a radio outside of my car for the last 15 years)
Also HDMI port would be sweet. There was a mini HDMI on Nokia E7.
With a couple of USB ports and HDMI one would not need a docking station which is also huge. Because if I need to carry a docking station everywhere with me, then I would ask myself the question, why do I carry a phone and not a notebook instead. So with an HDMI port one could travel with Librem 5 and the charger and still enjoy convergence out of home.
So to sum up. My wish would be:
- more RAM
- 2 USB-C (one for charging and one for plugging in a dongle).
- HDMI or micro HDMI port.
- keep the opportunity to get rid of / exchange the WiFi/Modem modules. I read that this might drop and it would be a pity. As wireless technologies are the big weakness for any security device and it is nice if one could physically remove them.