Many years ago I designed and made the 2m AM Fredbox 2m AM transceiver. At the time it was the smallest 2m transceiver I’d ever seen or used. Several close copies were made. It worked some impressive DX including several 60 mile handheld contacts and one over 100 miles to Brittany from the South Devon coast. All these were with whip antennas on the rig and not beams. Most QSOs were with locals. The power was only 10mW AM. It was ideal for contacts around Cambridge where I lived at that time.
Some years ago, I rebuilt the transceiver and had some decent QSOs yet again.
As with the Sixbox, I would suggest the design is taken as a springboard for your own version. It is certainly ripe for further development.