Thanks for everyone's input.
Instinctively I'm keen to avoid any separation between the emulsion and the paper. I'll try a hardener on the film first.
My first tests of completely drying the paper are promising. I remember hearing that catching the paper just on the turn between dryish and really dry was best. I might be messing up my process by paying too much attention to that advise.
Shanghai film is a law unto itself. It comes in a totally blank white box with a sticker haphazardly placed on it to tell you what it is. The box is a simple 2 layer nested box rather than the conventional 3 layer nested box that other films come with. Every time I get a new batch I feel like someone has had to tape up the windows in their bathroom to make it. The total failure to present it well or provide any technical information about it is strangely intoxicating. Against all rational judgement, I highly recommend it!