Hi @cederom,
For clarity, PacketCraft is the company developing the Cordio stack now (it’s not yet a new stack 
). Therefore any bug in the stack should be reported to PacketCraft.
The Cordio stack is still supported in Mbed OS and our intent is to update it regularly. It’s production ready has been used in high-volume shipments for years.
This is something we should make clearer, I can see how confusion could arise.
Regarding your other points - the Nordic “UART” is a basic service to emulate a simple serial port-style link. It’s not a standard BLE feature so this implementation is Nordic-specific.
In terms of firmware update we understand this is an important feature and have it in our backlog, but we need to prioritize it against other roadmap items.
Don