Choosing between server-rendered pages and a small SPA for an internal dashboard

We're building an internal dashboard for a dozen staff members. Mostly tables, filters and a few editable forms; no fancy animations. The backend already returns HTML for the rest of the application. A small SPA sounds attractive for instant filtering, but I don't want to add a build pipeline and client-side routing for three screens. At what point would you stop using server-rendered pages with a little JavaScript and reach for a full client-side app?