They actually make the tool you fabricated. Called torque adapters. Handy as hell. I've got these in metric and standard: https://www.mactools.ca/en-ca/NoVal...rive-Metric-Box-End-Torque-Adapter-Set-12-PT-
Yes, in another life long ago, I was a Snap on dealer. Would love to have the sets you linked but just passing through the house at 2am I had to go the DIY route. Those and some Weatherhead sockets....