What are you talking about?  St. Pius X approved of Catholics in schismatic/heretic territories (e.g. Orthodox areas) who had no access to the Catholic Mass to receive the Sacraments from the Orthodox.

It is the Catholic Church alone who has rights over the Sacraments, and the Church commands that the schismatics/heretics give them to Catholics ... not that they would be inclined to comply.  By receiving the Blessed Sacrament, moreover, you are preventing reception by a heretic/schismatic, who might otherwise receive.

I said what I am talking about. And I don't know which part you didn't understand.

If you are, other than I am, aware of a recommendation of the Church, to accept sacraments from heretics, then please be so kind and quote your source. I know of the CIC which basically says that it's not prohibited or punished, but I don't read that as a recommendation. There are footnotes, too. Also, it's chronologically after St. Pius X.

Then, there is St. Hermenegild, prominent for rejecting the sacrament from heretics in the hour of death.