I like this idea. We also have a per device plan as well as per user plan with 3 levels each.
Maybe we can do the same for per user by matching the contacts of a client as well.
Maybe we can do a select box in contacts and assets with managed contract select dropdown that is predefined under products and allow you to select the recurring invoice Number beside it
I'm not sure the best way of going about this but deff puts some thought that wasn't there before