Hi;
Wavelet layers can be created in processing softwares like PixInsight; I do not think that this is the source of the problem..
As collimation and focus were spot on my only concern is that there is simply not enough data...
I had a go with M51 and even with 6 hours of integration I was not satisfied...
I simply attached my Lum file who needs more and more hours...
M51; IMHO is an object that needs at least a minimum of 12 hours of integration to have a real nice result...
Astrophotography; an easy and slow hobby eating all of your time