Thats not the point. I already had a 4096 key and its already distributed and certified by people. I will not change all of my system back to 2048 just so I can

Thats not the point. I already had a 4096 key and its already distributed and certified by people. I will not change all of my system back to 2048 just so I can use a SmartCard. If I had started with Yubikeys when I started with GPG I would have used 2048 and updated when the Smartcard technology improved. Additionally I have not a huge need for gpg messages on my Smartphone, so its not a big problem.