A NAS is an unsupported configuration as indicated on the requirements page: https://portal.softrak.com/products/requirements.php
I believe it can be perceived as subverting the license agreement because of how lanpaks work. But I'll let Support comment on that if they want to.

Some have done a C drive install for multiple users in certain exceptions, but having installs on each pc is a real pain to maintain and will leave room for many problems such as mixed versions and breaking user setups and security groups, just to name a few. And I wouldn't count on support for that setup.

For the cost savings a NAS is providing, you might as well set up a peer to peer network so you can install to a share.