Nice image JJJ. Don't be afraid to use much longer subs though. If necessary use a LP filter. 10 minute subs will give you far more detail than 3 minutes subs. Even using really large numbers of subs at short exposure lengths will not overcome the noise that will pop out as a result of the signal not overwhelming the background ADU (this is probably not well explained).
If you are having trouble guiding then perhaps look for another solution so that you can guide for longer. I am not sure if there is some limiting factor that you have which requires such short subs.
Your images show incredible promise, but you just need to capture longer subs to achieve fantastic results. Just my opinion.
