Thanks for your quick reply. Yes, I want to make a plug-in that runs in the host I already have (also JUCE based). Swapping sample maps only wouldn't suffice. Rather swapping full instrument definitions that include a sample map, ADSR, filter, mods, panning, etc.
The forum does also not send emails (or they don't arrive). You'll need a domain and legitimate SPF, DKIM, PTR entries in the DNS. Or use a 3rd party SMTP service. Communication is a top priority for any project, if you want it to thrive.