Have plugged it and it's holding air. Need to take for a test ride though, as it was holding air before and only started pissing sealant everywhere when I was riding, presumably from being squashed when absorbing bumps, etc.
55psi (total weight is probably about 95kg - both I and it are heavy)
Sealant struggles at high pressures, sometimes it's just better to nurse a soft tire home rather than trying to pump it until it pisses out all sealant.
I'll plug anything that's not sealing by itself. Also, what pressure are you running?