Information displayed while printing is very limited.

[gbarbehenn]

More enhancement than bug. The printer only displays very limited information while printing - hotend and bed temperatures. Fixing the lack of display of thumbprints, when using USB communication, will go most of the way to fixing this. But, it would be useful to display elapsed printing time and current Z value.
The attached file has the total printing time (as a comment) and maximum Z-axis value (also as a comment). Ideally, the printer would show elapsed_printing_time vs. total_printing_time (as rescued from comments), and current_Z_value vs maximum_Z_value (also rescued from the comments)
EN3PRO_Base and clamp bottoms.zip