Hello digger from the future.
The best you can do to workaround this is
query query($uids: string = "[0x1d, 0x1e, 0x20, 0x21]") {
Uvar as (func: uid($uids))
query(func: has(follows)) @cascade
{
uid
follows @filter(uid_in(~follows, uid(Uvar)))
{
uid
}
}
}
Multiple blocks and use uid()