make -a as default ?

[avichou]

is it possible to make brew CU update all casks (included those with autod update on) by default ?

so that I won't have to type -a each time, and will simply have to enter brew cu -y

(side question , is it dangerous/not advised to update apps that are marked as "auto update" ? )

[yurikoles]

Persistent config is being implemented in #174

[ondrejfuhrer]

(side question , is it dangerous/not advised to update apps that are marked as "auto update" ? )

Not really, it's up to every person to decide, how they want to manage those casks, either through brew or let them auto-update. You can also combine both of the approaches, etc.