In my original testing for address scale-up with a Proton Messenger based client, I was measuring a memory cost of 115 KB per subscribed address in the client.
Now, after Rafi's recent changes, I am seeing a better than 7x improvement, to just under 16 KB per subscribed address. The downside, of course, is that this will make it about 7x harder for me to persuade my boss to buy me a Really Big Box. ( But I'll think of something... ) Thanks for the memory!