Hi Alice Tallents 

Unknown said:

I've read articles recommending download of Glossary Converter, but it looks as though this app doesn't support Japanese. Can anyone confirm this?

I can't confirm this.  In my experience it does support Japanese.

Unknown said:

Excelling MultiTerm is another app that is recommended, but the description suggests the free version can't handle a complex termbase structure. Do the paid versions support Japanese? And is it likely that this app would solve my issue?

Best to ask somoeone like Klaus Fleischmann but I would say Excelling MultiTerm would be able to support your requirements.

Unknown said:

Since I'm working in an inhouse environment, access to shareware/freeware sites is blocked, and I will need to request download internally, so want to be sure the tools will work before making that request and/or asking for budget. 

What shareware/freeware sites?  You get these apps from the SDL AppStore.

Unknown said:

Also, how does Studio 2017 handle the issue of exporting large & complex termbases into XLS-compatible formats?

No better than previous versions.  Glossary Converter or Excelling MultiTerm are better choices.  You could also play with LanguageCloud Terminology as this does support a better Excel export/import, but the first two suggestions are probably the tools you're looking for.

Unknown said:

Finally (apologies for multiple questions), will Studio 2019 introduce any changes/improvements re. exporting TBs for use in Excel?

No.