Things might have been different had full debutant Jonathan Keaveny not scuffed his shot wide having rounded Marlon Beresford.
With Miedzinski passing 16-year-old Danish debutant Jonas Raun, the resultant 7-2 advantage saw Swindon haul themselves back into the match.
He made the senior ranks when only 17 years 139 days old, then the club's youngest debutant.
Ted Doig is the oldest player to play for the Reds aged 41 years 165 days. He is also the oldest Reds debutant.
The other debutant was in the u/17 boys, Elijah Collins.