1: The file displayed in the visualizer will disappear when changing view angle but the stylus stays and moves with the cut. Is the file image painted in memory only once?
2: It would be handy if the line number was added to the console to accurately indicate the true location in the gcode. The start-from seems to be about 5 lines ahead and I usually correct it before restarting.
3: When restarting a job the spindle is not allowed to reach speed before cutting. I set the SETUP to 5 seconds and it seems to only affect initial job startup and adds to the pause in gcode I added in pre-processor .
Thanks for the submission James! Regarding your first point could you explain more what you’re seeing and confirm that you still see it in gSender version 1.5.3?
Regarding your other two items the reason for the line number being off has to do with another area we’re looking into where since gSender strips out blank lines and comments it often means that the line that we think it is compared to the actual file is different. Also to your 3rd point I just noted another, older request for the same thing so we’ll be looking into it 
In reply to first point, I still see the issue of disappearance of vector (Tool Paths) drawing when I inadvertently clicked on the “Feather” causing the astronaut cat to appear and when I clicked the feather again the grid lines and stylus reappeared (following the cut) but the vectors (Tool Paths) did not. They could only be restored by reloading the file.
Regarding the issue for the restarting after a pause, I go to console and issue a gcode (s22000m3) or whatever speed was set, to restart spindle before restarting job.
Tnx, Jim
Using app image on 64 Bit PI