Thanks for the frank (and on target) assessment and feedback.
Because of the secure server environment, yes, I think we would need a product that would be hosted on that server. From what I have seen, this would be a great product to choose to do that. As for multiple concurrent users accessing for editing, we could control that (I think) with the links at our end ... but the open communications ... I'm sure it could be technically worked out, but due to certain proprietary, etc. restrictions on our end, we would never get over that hurdle.
I would be very interesting in the new product (self hosting ... leasing?). Unfortunately, my timeframe for getting "something" up and running is only a few weeks (4 at most). I suspect that is too tight to expect you to be able to support.
I am also looking a just providing a link to the published calendar (published on your site / password protected) from our server. This is very workable. But, my thinking is to have the edit capability as if a single user ... all couple hundred potential users would have the same (single) log in info for editing.
(1) Is this allowed by your T&Cs? (save me the time of studying)
(2) I assume if a second logon was attempted while the first login was still editing, an error or "view-only" prompt would occur (?)
But let me know if/when that option is available.
Thanks again
Dan