I submitted the positive tests (dated late March/ early April) for our trip from Spain to Germany and they were recognized and given the OK for three of the four of us. For my son it said 'please report for a final check at checkin'. Yes all of us have separate email IDs, the IDs of the kids end up in my personal mail account.

On the way to Spain it cleared everything based on the ePLF for Spain and the new negative PCR tests (which Spain required at the time). On arrival in Spain the health autorities scanned the spanish ePLF and only my wife was 'randomly' selected to show all her papers. I didn't expect this LH preclearance to do any magic with the health authorities in Spain, it is just to reduce some work at checkin. The German BuPo also met our flight from Spain in MUC, but only did spot checks. Same story there: authorities will check based on their criteria.