The Present (Concessive) Subjunctive (Whether/If It Be) in Past Tense Cases

Did the present, concessive subjunctive (“if it be the case”; “whether it be the case”) ever have a place in past-tense sentences?

To my understanding, the subjunctive “were” and the conditionals in which “were” appears refer most often to present or to undefined time and are more applicable to present or future possibility than to past facts. But I’ve noticed in some older writers the subjunctive is inserted into indirect questions (“asked him if he were …”) as if the present subjunctive mood were back-shifted to chime with the past tense narrative. Isn’t this a (learned) mistake? And does the present subjunctive really fit into past actuality?

Thank you!