I haven't used this module in a while, and don't have the quick ability to do so now, but I recall you can set the fields up two ways, one that relies on the database and cron/caches, and the other that runs on each node view.
A quick look at the module page has this snippet:
You can also choose whether to store your computed field values in the
database with other content fields, or have them "calculated" on the
fly during node views.
so I would look into that option. I am pretty sure that if you store it in the database it only updates when that particular node is updated, but if you don't store it in the database, it is run on each node view. (Somewhat obviously this will have a performance impact if the computations are complex.)