I thought I was all clear for the 72hr transit visa but not sure now.

DXB - Shanghai - Taipei then Tokyo - shanghai - Dxb

British nationality.
China eastern airlines.

Dubai to Taipei but flight stops in kunming (2hrs, Same plane), then transit in shanghai (4hrs), then continue to Taipei.

Return is 10 days later: Tokyo - shanghai (65 hour stop over) then dubai with a 1hr stop over(Same plane) in kunming.

I read somewhere that you can only have one 72 hour transit? Will I be able to the get the standard 24 hour free transit on the way there and on the way back 10 days later the 72 hours as I will be only stopping over in shanghai on the way back on a direct flight from Tokyo - shanghai (Then on to Dubai 65 hours later)