We're in the process of researching how to setup a user training environment. We're currently doing user training in the production org, and want to get a away from that. We've got over 2,500 users so there is a pretty constant need for training.
In terms of environment type, has anyone successfully used dev orgs or scratch orgs for user training? These would be the least expensive environments, so any reason not to use them?
Also, has anyone got a recommendation on the most efficient way to populate the orgs with training data? I know there are a lot of options and just trying to narrow my focus to a few alternatives to research further.