What about this idea?
#3 and #4 teams in 1st-round groups advance into two new second-round groups (#3,#4 in 1st-round) of six.
The top two teams in each new group (#3,#4 in 1st-round) and the teams finishing third and fourth in the original second-round group (#1,#2 in 1st-round) will compete in one match on Friday to determine the qualifications for the Second Chance Qualifiers.