The script is not small simple, unfortunately, its part of my allsky software project:
github.com/aaronwmorris/indi-allsky/
Here are some example log messages from a doubled exposure. The camera appears to take the exposure and then hangs (a 9 second gap between messages). Below that is what a normal exposure looks like.
Doubled exposure
<code>2021-04-10 00:00:46,262 [INFO] MainProcess takeExposure() #108: Taking 9.239792 s exposure
2021-04-10 00:00:46,306 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:46,655 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:47,656 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:48,657 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:49,658 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:50,660 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:51,662 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:52,664 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:53,665 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:01:04,980 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:01:05,103 [INFO] MainProcess newBLOB() #66: new BLOB CCD1
2021-04-10 00:01:05,108 [INFO] MainProcess newBLOB() #73: Blob downloaded in 0.0041 s
2021-04-10 00:01:05,109 [INFO] MainProcess run() #784: Exposure received in 18.8462 s</code>
Normal exposure
<code>2021-04-10 00:00:31,245 [INFO] MainProcess takeExposure() #108: Taking 9.239792 s exposure
2021-04-10 00:00:31,286 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:31,717 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:32,718 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:33,719 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:34,721 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:35,722 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:36,723 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:37,724 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:38,725 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:40,648 [INFO] MainProcess newNumber() #87: new Number CCD_EXPOSURE for device SVBONY SV305 0
2021-04-10 00:00:40,772 [INFO] MainProcess newBLOB() #66: new BLOB CCD1
2021-04-10 00:00:40,777 [INFO] MainProcess newBLOB() #73: Blob downloaded in 0.0041 s
2021-04-10 00:00:40,778 [INFO] MainProcess run() #784: Exposure received in 9.5331 s</code>