Pruning and Dividing Anubias

Is there a general rule of how much rhizome to remove from an anubia? I
want to split my larger one, but I want to make sure to leave enough
rhizome/root/leaves to make sure it survives the division.

Also, the anubia recently had two blooms, once the flower has
deteriorated, should I remove that stalk? I know with land plants this
is commonly done...

Any help would be great!