Of course there is another way - it's SlickEdit
Why do one need to always start a process buffer when switching projects ?
BTW do you mean projects or workspaces ?
Env.vars. can be set per workspace (global for all contained projects).
You can also set env.vars per project build tool (running in process buffer).
Since switching workspaces or projects is very fast in SlickEdit, you can find a proper structure of your 'real' project e.g. one project/workspace or all projects in one workspace, ... which meets your requirements.
However, if you you really need a fresh process buffer each time you switch workspaces or projects you can achieve with little macro help. I could send/post an example if you want, but I don't favor this method as long as there is a standard way of getting things done.
HS2