We would like to see package credits to be applied to any services without having to program specific services. If services are used as hours, client should be allowed to use any number of session hours.
I have a similar interest, different application. We had setup packages to sell class packages, until we realized packages have to have specific service, and a specific number of each. Our packages are prepaid class accesses, and in exchange for prepaying (committing to more than one class) the client gets a better rate. After taking with support I discovered we had to use "memberships" instead of "packages", which felt confusing because a membership is by definition ongoing until the user stops it, where the package stops when it's consumed. At least that's how we understand it.
Then, we started using "memberships" which led to another discovery: any service assigned to a membership is no longer available for purchase by non-members. This is a problem as we have classes that are provided to both membership/package owners, and people that are walk-ins, or drop-ins as we say in the industry.
Because of this limitation we have had to duplicate the same services, one belongs to a membership and the other for drop-ins. This is really not convenient and looks odd from the clients' perspective when they are booking. You have the same service except one is for the package/membership, the other is for drop-ins in our case. ex. Service A & Service A for package owners. Someone will inevitably book the wrong one at one point or another.