If it had been LHR, I would have said yes. Last week, I did LHR-MRS and MRS-LHR back-to-back on separate tickets. The check-in agent at LHR had no difficulty printing both BPs; I had already OLCId for both flights.

But I would be wary about relying on an outstation being able to do this. I get the impression that there might be difficulties with IT systems and with insufficient agent knowledge (particularly if the agents concerned are not BA staff).