Web hosting and script providers: advise them of the policy and "Remix" designation. There's only a (known) handful.
Front-ends (mobile or desktop) and integration plugins: lots. Put together a contact list and advise recipients of the policy. Request a response/acknowledgement so we have a verified contact list for future reference.
Remix emails sent to: DreamHost, SimpleScripts, Softaculous, and Parallels.
OK I think we don't need to contact all authors of 'piwik' plugins, too much work, you already contacted dreamhost/simplescripts/etc.