Working with customers that have deployed (e.g. provisioned or configured) over 1,000 vPro systems today. Considering their client refresh cycle and so forth - not bad. In some cases - as soon as the ProvisionServer was configured - 100 clients (which were pre-provisioned and ready) would appear and be configured. This could occur within an hour or day - depending on what's going on in the environment and so forth. Pretty cool.
Planning and assisting environments for 10x and 100x that amount. As expected - this will occur according to client refresh rates which is estimated at 3-4 years.
Using enterprise mode configuration.
A few BKMS (e.g. Best Known Methods):
Have a target\future state in mind - understand how the client will be utilized within the system mgmt console and according to processes
Plan before deploy - configuration approach, architecture, etc
Have a community of resources - internal and external (like this community site). Use to post questions, ideas, and so forth.
The quick start guide on this community provides some addition insights and inputs.