Would a few roughly 300-ton gunboats be useful to the Royal Navy for patrol work and junior-officer commands?
Short answerOnly in local or forward-based roles; their range and support needs would make them poor substitutes for ships able to deploy globally.
NotesWhere the boats would operate determines their value. Small gunboats could work in confined or forward-based waters and might make sense as part of a Baltic squadron. They could not accompany task groups to the South Atlantic or Far East without an extensive network of bases and support. Establishing squadrons in several overseas theatres would also consume money needed for other ships. A cheap hull still carries costs in range, basing, and global force structure.