Thanks for the reply. I've been thinking about the process of pulling out the charge,
checking it's weight, and then using it to recharge the system..
But, maybe it would be safer to use brand new R410A..?.
I guess the main point of bleeding off the non-condensable gas, is to keep the pressure 'normal'.
So you can keep using the recovery tank without fighting with it's pressure..
I saw this 'guide' to preparing a new tank. Getting rid of all that nasty nitrogen, before use..
https://youtu.be/E6-DDjWvHHU