I believe all options you suggest are more than OK, but. Why don't you limit the trial with some capacity limits? Say, 1000 vms for installation. Of course, you

I believe all options you suggest are more than OK, but. Why don't you limit the trial with some capacity limits? Say, 1000 vms for installation. Of course, you'll need to have two artifacts: one for paying customers, and a second one to non-paying ones.