Random fact. The last game play off game in professional English football where the away goals rule was in force was our home win against Birmingham in 2000
Sorry it was the first year when the away goals didn’t count as a decider as I can remember dumb radio Sheffield commentator asking basset is it a shame away don’t count to decide after we had won 4-0 away and the only way away goals would have come into it would be if we lost 5-1 or more and so would have lost on the away goals rule also see link https://www.thesun.co.uk/sport/football/2232248/away-goals-count-football-league-playoffs-efl/
I've had a nightmare. I read an article saying that they ended in the 1999-2000 season and thought it meant at the end of it. Just checked wiki and they say BEFORE that season like you say. If anyone wants me I'll be hiding behind the sofa.