Inch mode Gcode failing with certain designs and $fb=440.20; mm OK

[cmcgrath5035]

Two recent Forum items have good datasets and reveal the inch mode Gcode bug that seems to show itself in $fb=440.20 off and on.

This thread, the Chillipeppr logo (inch mode) failing on G2 and G3 moves https://www.synthetos.com/topics/tinyg-inch-mm/#post-9388

This thread, A user job, reveals the issue with all G1 moves https://groups.google.com/d/msg/chilipeppr/ZTcBVuMznxk/gvsQZqDAFQAJ

Both are Ox machines - does $_tr=60mm contribute to this issue?