I was worried this might happen. I'm switching to device assigned later this summer so my App Catalog is going to become humongous. At my last district Self Service was taking a minute to download the first time for ~140 apps. Although the next times it seemed to cache much of the data and just checked for updates.

I would go ahead and start testing hard and now. We are trying different processor strengths and numbers for our two front ends. I will share all my findings man and let you know how it goes.

The more ipads loading self-service at one the worst it is.

We have the JAMF hosted solution, we've had this issue from our initial rollout and the time gets worse as you have 350 students all on boarding at the same time. I just wish JAMF support was just up front that this is what is happening. Our times seem to vary anywhere from 40-50 seconds to 5 minutes. I do have about 6 apps we push/auto install to the students and they do not seem to have the issue if getting their device assigned licenses. I would think licenses start assigning as the JSS knows the iPad is scoped rather than waiting for SS. We were given the suggestion of unscoping most apps until SS had been opened the first time which is not practical. I'll have to test just letting the iPad sit for awhile before opening SS the first time.

I was testing self service a few weeks ago and it was very slow. I've decided to stick with user VPP and have the students download apps via the purchased tab in the app store.