It is fairly common to use the same options over and over in all paranoid models. Like, if you decide to use boolean values for the deleted column it is likely that you do that for all models not only for some.
Recently I added double_tap_destroys_fully: false to all of the acts_as_paranoid calls in different models because we decided that this is some behaviour we actually don't want to have.

It would be nice to have the possibility to configure the gem centrally, not on a per-model-basis.

I think it could be a good idea to hook into Rails.application.config since the gem is strictly bound to ActiveRecord and is very likely that Rails is used as a whole.

edit: To be clear, all those settings should still be overridable in the acts_as_paranoid call and just tweak the currently hard coded default options in lib/acts_as_paranoid.rb#L25-L31.

I am happy to submit a pull request with a proposal if this is desired.