Embarrasingly, after mucking around with all the other tools, I just retried using Subsurfarce (thinking I would produce a dump), and now it loads all dives.
I have tried downloading the logged dives with the latest OSTCProfile from OSTCTools beta9. It does not produce any errors. Attached profiles as ostctools_profiles.zip.
I have tried using the libdivecomputer unversal test program: [pre]universal.exe -v -l ostc3.log -d ost3.xml -b ostc3 COM4[/pre ...