a quick bump and +1 on this :)
more and more plugins are becoming available native on Linux, so using a linux machines as a server running VEP is really very attactive.
I recognise you use eLicenser, but how about adopting a slightly different model, until they port it to Linux
the VEP server and VEP plugins (event input, audio input etc) only runs on Mac/PC (with eLicenser)
VEP instances can run on Linux, but can only be 'started' by the VEP server (above), when it starts it contacts the VEP server to aquire authorization, if it fails it cannot start*
this wouldn't support linux users using linux based daws (they will need to wait for eLicense) BUT, it will allow Mac/PC users to start using Linux as a 'plugin server farm', which would be great as linux can be configured to be much more efficient/lean than mac/pcs.
(I dont know much about VSL, but I assume it could also be run on the linux server, again using the same 'authorisation' on the server instance model)
* note: probably worth noting.. its not worth anyone hacking the linux instance anyway, as it can only be used by a VEP plugin, which are only available on mac/pc, and then require the server... which needs eLicenser to run. so the linux instance is worthless without the VEP Server/eLicenser