Is Resource Management limited only to paid users?

We are a software development company and we use Smartsheet as a project management tool to onboard new clients. These projects have thousands of tasks and resources that are internal (our team) and external (our clients' teams).

As our company grows and the number of simultaneous onboard projects increase, we now need to start tracking resource management across multiple projects for both internal (our company users) and external users (our clients' users).

However, when I research this feature, I see that this functionality is only applicable to paid users??? Is that right? When I try to create resource views, it only allows me to select the short list of paid users? I must be doing something wrong!

All users that we need to track resource allocation for are editors; in other words, free users. Once the project is completed, I will no longer needs those users so I cannot buy licenses at $25 per user per month just to temporarily track resource allocation.

Please let me know how I can turn editors into trackable resources for resource allocation management.

Thank you.