I recently did a LHR-DUB-LHR-MAN-LHR-GLA-LHR day trip involving several B2B's (to cheaply earn segments for my new FFP).
DUB: Reasonable. 'Alternative' airside transfer was open, and the process outlined by
BugAlugs in
this post remains valid.
MAN: Poor. Since the move to T2 in Oct-25, arrivals are now segregated from departures. Details in
this post, with photos
here
GLA: Excellent. Continues to arrive directly into the departures area.