Portable Install and VST3

Can VST3 dlls be copied over to your REAPER portable install thumb drive like most free VST2 dlls? I think the only ones I have right now in VST3 are the Melda which uses an installer, but I believe it's files can still be moved without breaking. Sorry, this is my first go at portable install.

No. VST3 plugins have their own folder in Program Files/Common Files.

Yes , melda-vst3 can be moved. the installer writes melda-locations in the registry and the vst3 read from there. tested it here with the little meldadrummer

OK so that's plugin specific - it has to be coded for that. You can't do this with all VST3 plugins, AFAIK.

Thanks, so are you saying that the installer still needs to be run on the host machine or at the least a registry edit done? I want to use the portable install to take with me and use on multiple PCs. At the studio we have a desktop, and I have a personal and work laptop I sometimes use as well. I have 4.7 installed on each, but it seems I keep making little adjustments to preferences and then forget to back up the prefs and take with me to the studio (by studio I mean band practice at someone's house).

It depends if the plugin is portable or not. To be portable it requires that it doesn't write to any hardcoded paths or registry, at least not essential things it cannot 'regenerate' if they don't exist. If it does write to the registry but it can work without having them pre-generated (by installer etc), then it's said the application is portable but not stealth. Easiest way to check if a VST is portable or not is to install it in a Sandbox or Virtual Machine first (sandbox is far easier / less hassle) and then inspect the registry and/or files it created. Or just copy the .dll/vst3 after installing in sandbox and see if it runs outside of the sandbox without the registry or hardcoded files. But tbh this is one of the reasons, apart from bloat, of why I hate VST3. At least REAPER allows you to specify custom paths to vst3 so you can move them around.