May be it could be an idea for future versions..
A second camera (slave) could be added directly in main SGP interface
Then with options there could be defined some conditions to have dithering based on exposure time. Condition must be that slave camera exposure is the same or less then master camera..for example:
Main camera exposure time: 10 minutes
Slave camera: 3 minutes
While the main camera is taking the 10minutes exposure the slave camera takes 3 exposures, and wait a minute..
When the main camera completes the exposure, sgp does dither, and begin again the cycle, 1x10minutes on main, 3x3minutes and 1min wait on slave, dither and so on..
This approach could be very interesting if exposure duration ratio on main/slave is 1:1 or multiples.. but could work even if there are strange ratios.. for example 10 minutes on main, 6 minutes on slave (but slave have to wait 4minutes)
For main camera everything stays the same as now because it's the only camera that pilot phd and dither requests..
Hope it helps
Andrea