Remember you can usually achieve this from the console as described in @sc-steemit's article and linked by the OP here. Be careful when editing your config file. In fact, everyone should read the linked article anyway as it contains a lot of good practice we should all be aware of. A note on encrypting before you all fly off and do it:
If you encrypt your wallet, all prior backups become useless. Make new ones.
If you forget your encryption key, gg no re.
That being said, it is good practice to encrypt your wallet and only unlock it for staking.
Thank you for your added experienced advice.