More updates from CGK today. It looks like the escalators to transfers were working today so theoretically it is possible to do a B2B at CGK with hand baggage only.
However, those who are familiar with the airport will appreciate the walking time required to get from one end of the airport to the other for the transfers will find it a challenge at the best of times to get across the airport if you are on opposite ends. I still would not recommend doing a B2B.
I was one of the victims who had a CMB-CGK cancellation so was routed CMB-KUL-CGK with a two hour connection. It seemed that the transfers desk at KUL on the C Gates were lacking with staff so two hours was just about sufficient to transfer and get a boarding pass. However, I do think I was just incredibly unlucky today.