Sphere 3 - Full Mode
Who Should Use Full Mode?
Users who wish to take advantage of the privacy features of Sphere should use Full Mode. This includes shielded addresses and private messaging. Keep in mind that once an account has been used in Full Mode, your previously encrypted private keys will be place in an unencrypted file, the wallet.dat.
Full Mode requires a complete copy of the blockchain.
Recommendation
Consider creating one Light Mode Account for transparent addresses. Never change it into Full Mode.
Create another Account and set it for Full Mode and use this Account for private addresses and private messaging.