Closing GCode files or switching between them?

I happen to be running qtdragon_hd, but I assume this to be more of a general question than UI specific.

If I have no file loaded and I'm probing around my stock, it updates very quickly without any issues. However if I load a large file (over 10k lines), after each probe it seems that it has to reload the file to redraw the paths at the new offsets, which dramatically slows down the probing process. I can simply load up an empty gcode file while probing then load up the large file, however this leaves me with a really long list of files in the loaded files dropdown list. Also, when I select a different file from that dropdown, it doesn't appear to actually load it / activate it?

So my question is, is there a way to either:

1) "Close" a file so it's no longer loaded in LinuxCNC without closing LinuxCNC itself
or
2) Switch between loaded files and actually have the newly selected file become active (not just show the gcode in the MDI box)

In Axis there is preview control.

linuxcnc.org/docs/stable/html/gui/axis.h...axis:preview-control

At top of gcode file, together with  Toggle Skip lines with "/"  ,it is easy to control the preview on/off
The comment is case sensitive

/ (AXIS,stop)